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VHD (file format)

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A file format is a standard way that information is encoded for storage in a computer file . It specifies how bits are used to encode information in a digital storage medium. File formats may be either proprietary or free .

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138-488: VHD ( Virtual Hard Disk ) and its successor VHDX are file formats representing a virtual hard disk drive (HDD). They may contain what is found on a physical HDD, such as disk partitions and a file system , which in turn can contain files and folders . They are typically used as the hard disk of a virtual machine , are built into modern versions of Windows , and are the native file format for Microsoft 's hypervisor ( virtual machine system), Hyper-V . The format

276-509: A home network ; and new multimedia tools such as Windows DVD Maker . Windows Vista included version 3.0 of the .NET Framework , allowing software developers to write applications without traditional Windows APIs . There are major architectural overhauls to audio, display, network, and print sub-systems; deployment, installation, servicing, and startup procedures are also revised. It is the first release of Windows built on Microsoft's Trustworthy Computing initiative and emphasized security with

414-454: A release to manufacturing (RTM) build is the final version of code shipped to retailers and other distributors, the purpose of a pre-RTM build is to eliminate any last "show-stopper" bugs that may prevent the code from responsibly being shipped to customers, as well as anything else that consumers may find troublesome. Thus, it is unlikely that any major new features would be introduced; instead, work would focus on Vista's fit and finish. In just

552-549: A 64-bit install media can acquire this media through the Windows Vista Alternate Media program. The Ultimate edition includes both 32-bit and 64-bit media. The digitally downloaded version of Ultimate includes only one version, either 32-bit or 64-bit, from Windows Marketplace. The maximum amount of RAM that Windows Vista supports varies by edition and processor architecture, as shown in the table. All editions except Windows Vista Starter support both

690-494: A 720 KB low-density, 1.44 MB high-density or 1.68 MB DMF 3.5-inch floppy disk can be mounted by Virtual PC. Other virtual machine software such as VMWare Workstation and VMware Player can mount raw floppy images in the same way. Windows Virtual PC for Windows 7 (version 6.1) does not offer a user interface for manipulating virtual floppy disks; however, it still supports physical and virtual floppy disks via scripting . Under Hyper-V, VFD files are usable through

828-569: A Microsoft blog, there are three choices for OpenGL implementation on Vista. An application can use the default implementation, which translates OpenGL calls into the Direct3D API and is frozen at OpenGL version 1.4, or an application can use an Installable Client Driver (ICD), which comes in two flavors: legacy and Vista-compatible. A legacy ICD disables the Desktop Window Manager , a Vista-compatible ICD takes advantage of

966-473: A September 23, 2005 front-page article in The Wall Street Journal , Microsoft co-president Jim Allchin , who had overall responsibility for the development and delivery of Windows, explained how development of Longhorn had been "crashing into the ground" due in large part to the haphazard methods by which features were introduced and integrated into the core of the operating system, without

1104-596: A VHD file as a drive letter in Windows 7/Server 2008 and newer. For situations where mounting a VHD within the operating system is undesirable, several programs enable software developers to inspect and modify VHD files, including .NET DiscUtils, WinImage, and R1soft Hyper-V VHD Explorer. 7-Zip supports extraction and inspection of VHD files. Virtual Floppy Disk (VFD) is a related file format used by Microsoft Virtual PC, Microsoft Automated Deployment Services and Microsoft Virtual Server 2005. A VFD that contains an image of

1242-487: A blog entry which decried the development process of Windows Vista, stating that "The code is way too complicated, and that the pace of coding has been tremendously slowed down by overbearing process." The same post also described Windows Vista as having approximately 50 million lines of code , with about 2,000 developers working on the product. During a demonstration of the speech recognition feature new to Windows Vista at Microsoft's Financial Analyst Meeting on July 27, 2006,

1380-481: A boot PIN being required too. A variety of other privilege-restriction techniques are also built into Vista. An example is the concept of "integrity levels" in user processes, whereby a process with a lower integrity level cannot interact with processes of a higher integrity level and cannot perform DLL–injection to processes of a higher integrity level. The security restrictions of Windows services are more fine-grained, so that services (especially those listening on

1518-434: A byte frequency distribution to build the representative models for file type and use any statistical and data mining techniques to identify file types. There are several types of ways to structure data in a file. The most usual ones are described below. Earlier file formats used raw data formats that consisted of directly dumping the memory images of one or more structures into the file. This has several drawbacks. Unless

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1656-482: A clear focus on an end-product. Allchin went on to explain how in December 2003, he enlisted the help of two other senior executives, Brian Valentine and Amitabh Srivastava, the former being experienced with shipping software at Microsoft, most notably Windows Server 2003, and the latter having spent his career at Microsoft researching and developing methods of producing high-quality testing systems. Srivastava employed

1794-408: A company logo may be needed both in .eps format (for publishing) and .png format (for web sites). With the extensions visible, these would appear as the unique filenames: " CompanyLogo.eps " and " CompanyLogo.png ". On the other hand, hiding the extensions would make both appear as " CompanyLogo ", which can lead to confusion. Hiding extensions can also pose a security risk. For example,

1932-427: A direct effect on its development. This effort has resulted in a number of new security and safety features and an Evaluation Assurance Level rating of 4+. User Account Control , or UAC is perhaps the most significant and visible of these changes. UAC is a security technology that makes it possible for users to use their computer with fewer privileges by default, to stop malware from making unauthorized changes to

2070-520: A few bytes long. The metadata contained in a file header are usually stored at the start of the file, but might be present in other areas too, often including the end, depending on the file format or the type of data contained. Character-based (text) files usually have character-based headers, whereas binary formats usually have binary headers, although this is not a rule. Text-based file headers usually take up more space, but being human-readable, they can easily be examined by using simple software such as

2208-473: A few days, developers had managed to drop Vista's bug count from over 2470 on September 22 to just over 1400 by the time RC2 shipped in early October. However, they still had a way to go before Vista was ready to RTM. Microsoft's internal processes required Vista's bug count to drop to 500 or fewer before the product could go into escrow for RTM. For most of the pre-RTM builds, only 32-bit editions were released. On June 14, 2006, Windows developer Philip Su posted

2346-448: A file based on the end of its name, more specifically the letters following the final period. This portion of the filename is known as the filename extension . For example, HTML documents are identified by names that end with .html (or .htm ), and GIF images by .gif . In the original FAT file system , file names were limited to an eight-character identifier and a three-character extension, known as an 8.3 filename . There are

2484-401: A file format is to use information regarding the format stored inside the file itself, either information meant for this purpose or binary strings that happen to always be in specific locations in files of some formats. Since the easiest place to locate them is at the beginning, such area is usually called a file header when it is greater than a few bytes , or a magic number if it is just

2622-416: A file unusable (or "lose" it) by renaming it incorrectly. This led most versions of Windows and Mac OS to hide the extension when listing files. This prevents the user from accidentally changing the file type, and allows expert users to turn this feature off and display the extensions. Hiding the extension, however, can create the appearance of two or more identical filenames in the same folder. For example,

2760-401: A formal specification document, letting precedent set by other already existing programs that use the format define the format via how these existing programs use it. If the developer of a format does not publish free specifications, another developer looking to utilize that kind of file must either reverse engineer the file to find out how to read it or acquire the specification document from

2898-399: A hierarchical structure, known as a conformance hierarchy. Thus, public.png conforms to a supertype of public.image , which itself conforms to a supertype of public.data . A UTI can exist in multiple hierarchies, which provides great flexibility. In addition to file formats, UTIs can also be used for other entities which can exist in macOS, including: In IBM OS/VS through z/OS ,

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3036-463: A host operating system present. Windows Server 2008 R2 is also compatible with this feature. Later, both Windows 10 Home and Windows 10 Pro support the VHD/VHDX Boot feature. The VHD format has a built-in limitation of just under 2 TiB (2048 GiB ) for the size of any dynamic or differencing VHDs. This is due to a sector offset table that only allows for the maximum of a 32-bit quantity. It

3174-561: A hybrid drive can be spun down when not in use. Another new technology called SuperFetch utilizes machine learning techniques to analyze usage patterns to allow Windows Vista to make intelligent decisions about what content should be present in system memory at any given time. It uses almost all the extra RAM as disk cache . In conjunction with SuperFetch, an automatic built-in Windows Disk Defragmenter makes sure that those applications are strategically positioned on

3312-424: A large horizontal pane that appeared under the toolbars. A new search interface allowed for filtering of results, searching for Windows help, and natural-language queries that would be used to integrate with WinFS. The animated search characters were also removed. The "view modes" were also replaced with a single slider that would resize the icons in real-time, in the list, thumbnail, or details mode, depending on where

3450-460: A large number of new application programming interfaces. Chief among them is the inclusion of version 3.0 of the .NET Framework , which consists of a class library and Common Language Runtime . Version 3.0 includes four new major components: These technologies are also available for Windows XP and Windows Server 2003 to facilitate their introduction to and usage by developers and end-users. There are also significant new development APIs in

3588-442: A limited number of three-letter extensions, which can cause a given extension to be used by more than one program. Many formats still use three-character extensions even though modern operating systems and application programs no longer have this limitation. Since there is no standard list of extensions, more than one format can use the same extension, which can confuse both the operating system and users. One artifact of this approach

3726-533: A limited subset of features planned for Longhorn, in particular fast file searching and integrated graphics and sound processing, but appeared to have impressive reliability and performance compared to contemporary Longhorn builds. Most Longhorn builds had major Windows Explorer system leaks which prevented the OS from performing well, and added more confusion to the development teams in later builds with more and more code being developed which failed to reach stability. In

3864-414: A malicious user could create an executable program with an innocent name such as " Holiday photo.jpg.exe ". The " .exe " would be hidden and an unsuspecting user would see " Holiday photo.jpg ", which would appear to be a JPEG image, usually unable to harm the machine. However, the operating system would still see the " .exe " extension and run the program, which would then be able to cause harm to

4002-943: A new API, and is fully compatible with the Desktop Window Manager. At least two primary vendors, ATI and NVIDIA provided full Vista-compatible ICDs. However, hardware overlay is not supported, because it is considered as an obsolete feature in Vista. ATI and NVIDIA strongly recommend using compositing desktop/ Framebuffer Objects for same functionality. Windows Vista is the first Microsoft operating system: Some notable Windows XP applications and features have been replaced or removed in Windows Vista, including Active Desktop , MSN Explorer , HyperTerminal , Messenger service NetMeeting , NTBackup , and Windows Messenger . Several multimedia features, networking features, and Shell and Windows Explorer features such as

4140-408: A particular file's format, with each approach having its own advantages and disadvantages. Most modern operating systems and individual applications need to use all of the following approaches to read "foreign" file formats, if not work with them completely. One popular method used by many operating systems, including Windows , macOS , CP/M , DOS , VMS , and VM/CMS , is to determine the format of

4278-414: A piece of malicious software to compromise the system, or disable the encryption. BitLocker can work in conjunction with a Trusted Platform Module (TPM) cryptoprocessor (version 1.2) embedded in a computer's motherboard , or with a USB key. However, as with other full disk encryption technologies, BitLocker is vulnerable to a cold boot attack , especially where TPM is used as a key protector without

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4416-564: A protected mode, which operates with lower permissions than the user and runs in isolation from other applications in the operating system, preventing it from accessing or modifying anything besides the Temporary Internet Files directory. Microsoft's anti-spyware product, Windows Defender , has been incorporated into Windows, protecting against malware and other threats. Changes to various system configuration settings (such as new auto-starting applications) are blocked unless

4554-708: A single host machine . This method enables developers to test software on different operating systems without the cost or hassle of installing a second hard disk or partitioning a single hard disk into multiple volumes. The ability to directly modify a virtual machine 's hard disk from a host server supports many applications, including: VHDX was added in Hyper-V in Windows Server 2012 to add larger storage capacity, data corruption protection, and optimizations to prevent performance degradation on large-sector physical disks. VHDs are implemented as files that reside on

4692-441: A sorted index). Also, data must be read from the file itself, increasing latency as opposed to metadata stored in the directory. Where file types do not lend themselves to recognition in this way, the system must fall back to metadata. It is, however, the best way for a program to check if the file it has been told to process is of the correct format: while the file's name or metadata may be altered independently of its content, failing

4830-431: A specialized editor or IDE . However, this feature was often the source of user confusion, as which program would launch when the files were double-clicked was often unpredictable. RISC OS uses a similar system, consisting of a 12-bit number which can be looked up in a table of descriptions—e.g. the hexadecimal number FF5 is "aliased" to PoScript , representing a PostScript file. A Uniform Type Identifier (UTI)

4968-549: A subset of the functions in the diskpart command line tool. VHDs known as vdisk in diskpart can be created, formatted, attached (mounted), detached (unmounted), merged (for differencing VHDs), and compacted (for VHDs on an NTFS host file system). Compacting is typically a two step procedure, first unused sectors in the VHD are filled with zeros, and then diskpart can use the NTFS feature of sparse files to eliminate runs of zeros in

5106-487: A team of core architects to visually map out the entirety of the Windows operating system, and to proactively work towards a development process that would enforce high levels of code quality, reduce interdependencies between components, and in general, "not make things worse with Vista". Since Microsoft decided that Longhorn needed to be further componentized, work started on builds (known as the Omega-13 builds, named after

5244-583: A team. The name of the lab in which any given build originated is shown as part of the build label, and the date and time of the build follow that. Some builds (such as Beta 1 and Beta 2) only display the build label in the version information dialog (Winver). The icons used in these builds are from Windows XP. At the Windows Hardware Engineering Conference (WinHEC) in May 2003, Microsoft gave their first public demonstrations of

5382-485: A text editor or a hexadecimal editor. As well as identifying the file format, file headers may contain metadata about the file and its contents. For example, most image files store information about image format, size, resolution and color space , and optionally authoring information such as who made the image, when and where it was made, what camera model and photographic settings were used ( Exif ), and so on. Such metadata may be used by software reading or interpreting

5520-494: A time travel device in the film Galaxy Quest ) that would componentize existing Windows Server 2003 source code, and over time add back functionality as development progressed. Future Longhorn builds would start from Windows Server 2003 Service Pack 1 and continue from there. This change, announced internally to Microsoft employees on August 26, 2004, began in earnest in September, though it would take several more months before

5658-502: A value in a company/standards organization database), and the 2 following digits categorize the type of file in hexadecimal . The final part is composed of the usual filename extension of the file or the international standard number of the file, padded left with zeros. For example, the PNG file specification has the FFID of 000000001-31-0015948 where 31 indicates an image file, 0015948

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5796-638: A way of identifying what type of file was attached to an e-mail , independent of the source and target operating systems. MIME types identify files on BeOS , AmigaOS 4.0 and MorphOS , as well as store unique application signatures for application launching. In AmigaOS and MorphOS, the Mime type system works in parallel with Amiga specific Datatype system. There are problems with the MIME types though; several organizations and people have created their own MIME types without registering them properly with IANA, which makes

5934-428: A well-designed magic number test is a pretty sure sign that the file is either corrupt or of the wrong type. On the other hand, a valid magic number does not guarantee that the file is not corrupt or is of a correct type. So-called shebang lines in script files are a special case of magic numbers. Here, the magic number is human-readable text that identifies a specific command interpreter and options to be passed to

6072-491: A year later. Windows Vista was succeeded by Windows 7 in 2009. Mainstream support for Windows Vista ended on April 10, 2012 and extended support ended on April 11, 2017. Microsoft began work on Windows Vista, known at the time by its codename "Longhorn", in May 2001, five months before the release of Windows XP . It was originally expected to ship in October 2003 as a minor step between Windows XP and "Blackcomb", which

6210-528: Is a major release of the Windows NT operating system developed by Microsoft . It was the direct successor to Windows XP , released five years earlier, which was then the longest time span between successive releases of Microsoft Windows. It was released to manufacturing on November 8, 2006, and over the following two months, it was released in stages to business customers, original equipment manufacturers (OEMs), and retail channels. On January 30, 2007, it

6348-528: Is a method used in macOS for uniquely identifying "typed" classes of entities, such as file formats. It was developed by Apple as a replacement for OSType (type & creator codes). The UTI is a Core Foundation string , which uses a reverse-DNS string. Some common and standard types use a domain called public (e.g. public.png for a Portable Network Graphics image), while other domains can be used for third-party types (e.g. com.adobe.pdf for Portable Document Format ). UTIs can be defined within

6486-566: Is a new architecture with more advanced shader support, and allows the graphics processing unit to render more complex scenes without assistance from the CPU. It features improved load balancing between CPU and GPU and also optimizes data transfer between them. WDDM also provides video content playback that rivals typical consumer electronics devices. It does this by making it easy to connect to external monitors, providing for protected HD video playback, and increasing overall video playback quality. For

6624-407: Is a risk that the file format can be misinterpreted. It may even have been badly written at the source. This can result in corrupt metadata which, in extremely bad cases, might even render the file unreadable. A more complex example of file headers are those used for wrapper (or container) file formats. One way to incorporate file type metadata, often associated with Unix and its derivatives,

6762-408: Is aimed at low-powered computers with availability only in emerging markets. Windows Vista Home Basic is intended for budget users. Windows Vista Home Premium covers the majority of the consumer market and contains applications for creating and using multimedia; the home editions consequentally cannot join a Windows Server domain . For businesses, there are three editions as well. Windows Vista Business

6900-450: Is all about: "bringing clarity to your world" (a reference to the three marketing points of Vista—Clear, Connected, Confident), so you can focus on what matters to you". Microsoft co-president Jim Allchin also loved the name, saying that "Vista creates the right imagery for the new product capabilities and inspires the imagination with all the possibilities of what can be done with Windows—making people's passions come alive." After Longhorn

7038-449: Is an extensible scheme of persistent, unique, and unambiguous identifiers for file formats, which has been developed by The National Archives of the UK as part of its PRONOM technical registry service. PUIDs can be expressed as Uniform Resource Identifiers using the info:pronom/ namespace. Although not yet widely used outside of the UK government and some digital preservation programs,

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7176-659: Is calculated by multiplying 2 by 512 bytes for each sector. The C × H × S formula in the VHD specification allows a maximum of 65535×16×255 sectors. About 127 GiB is also the limit for VHDs in Windows Virtual PC . For fewer than 65535×16×63 sectors (about 31 GiB) the CHS-value in the VHD footer uses a minimum of H = 4 and a maximum of H = 16 heads with S = 17, 31, or 63 sectors per track. The CHS algorithm then determines C = ( T / S )/ H . The specification does not discuss cases where

7314-456: Is capable of running all editions of Windows Vista although some of the special features and high-end graphics options may require additional or more advanced hardware. A Vista Premium Ready PC can take advantage of Vista's high-end features. Windows Vista's Basic and Classic interfaces work with virtually any graphics hardware that supports Windows XP or 2000; accordingly, most discussion around Vista's graphics requirements centers on those for

7452-504: Is dimmed, and only the authorization window is active and highlighted. The intent is to stop a malicious program from misleading the user by interfering with the authorization window, and to hint to the user about the importance of the prompt. Testing by Symantec Corporation has proven the effectiveness of UAC. Symantec used over 2,000 active malware samples, consisting of backdoors , keyloggers , rootkits , mass mailers, trojan horses , spyware , adware , and various other samples. Each

7590-594: Is encoded in one of various character encoding schemes . Some file formats, such as HTML , scalable vector graphics , and the source code of computer software are text files with defined syntaxes that allow them to be used for specific purposes. File formats often have a published specification describing the encoding method and enabling testing of program intended functionality. Not all formats have freely available specification documents, partly because some developers view their specification documents as trade secrets , and partly because other developers never author

7728-448: Is not the case with Vista, which includes more comprehensive wireless networking support. For graphics, Vista introduces a new Windows Display Driver Model and a major revision to Direct3D . The new driver model facilitates the new Desktop Window Manager , which provides the tearing -free desktop and special effects that are the cornerstones of Windows Aero. Direct3D 10, developed in conjunction with major graphics card manufacturers,

7866-424: Is small, and/or that chunks do not contain other chunks; many formats do not impose those requirements. The information that identifies a particular "chunk" may be called many different things, often terms including "field name", "identifier", "label", or "tag". The identifiers are often human-readable, and classify parts of the data: for example, as a "surname", "address", "rectangle", "font name", etc. These are not

8004-425: Is sometimes useful to modify a VHD file without booting an operating system. Hyper-V features offline VHD manipulation, providing administrators with the ability to securely access files within a VHD without having to instantiate a virtual machine. This provides administrators with granular access to VHDs and the ability to perform some management tasks offline. The Windows Disk Management MMC plugin can directly mount

8142-874: Is specifically designed for small and medium-sized enterprises , while Windows Vista Enterprise is only available to Software Assurance customers. Windows Vista Ultimate contains all features from the Home and Business editions, as well as Windows Ultimate Extras . In the European Union , Home Basic N and Business N variants without Windows Media Player are also available due to sanctions brought against Microsoft for violating anti-monopoly laws ; similar sanctions exist in South Korea . Windows Vista includes four distinct visual styles: Computers capable of running Windows Vista are classified as Vista Capable and Vista Premium Ready . A Vista Capable or equivalent PC

8280-427: Is that the system can easily be tricked into treating a file as a different format simply by renaming it — an HTML file can, for instance, be easily treated as plain text by renaming it from filename.html to filename.txt . Although this strategy was useful to expert users who could easily understand and manipulate this information, it was often confusing to less technical users, who could accidentally make

8418-648: Is the standard number and 000000001 indicates the International Organization for Standardization (ISO). Another less popular way to identify the file format is to examine the file contents for distinguishable patterns among file types. The contents of a file are a sequence of bytes and a byte has 256 unique permutations (0–255). Thus, counting the occurrence of byte patterns that is often referred to as byte frequency distribution gives distinguishable patterns to identify file types. There are many content-based file type identification schemes that use

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8556-479: Is to store a "magic number" inside the file itself. Originally, this term was used for a specific set of 2-byte identifiers at the beginnings of files, but since any binary sequence can be regarded as a number, any feature of a file format which uniquely distinguishes it can be used for identification. GIF images, for instance, always begin with the ASCII representation of either GIF87a or GIF89a , depending upon

8694-669: Is used by Hyper-V . VHDX format is optimized for both HDD and SSD. File format Some file formats are designed for very particular types of data: PNG files, for example, store bitmapped images using lossless data compression . Other file formats, however, are designed for storage of several different types of data: the Ogg format can act as a container for different types of multimedia including any combination of audio and video , with or without text (such as subtitles ), and metadata . A text file can contain any stream of characters, including possible control characters , and

8832-516: The 32-bit ( x86 ) architecture and the additional 64-bit ( x86-64 ) instruction set extensions, which Vista was the first consumer home release of Windows to support. Intel IA-64 Itanium support however is exclusively limited to the Vista-based Windows Server 2008 . The maximum number of logical processors in a PC that Windows Vista supports is: 32 for 32-bit; 64 for 64-bit. The maximum number of physical processors in

8970-638: The GIF file format required the use of a patented algorithm, and though the patent owner did not initially enforce their patent, they later began collecting royalty fees . This has resulted in a significant decrease in the use of GIFs, and is partly responsible for the development of the alternative PNG format. However, the GIF patent expired in the US in mid-2003, and worldwide in mid-2004. Different operating systems have traditionally taken different approaches to determining

9108-919: The Luna visual style are no longer available. Support for the original release of Windows Vista (without a service pack) ended on April 13, 2010. Windows Vista Service Pack 1 was retired on July 12, 2011, and Windows Vista Service Pack 2 reached its end of support on April 11, 2017. Several Windows Vista components are upgradable to the latest versions, which include new versions introduced in later versions of Windows, and other major Microsoft applications are available. These latest versions for Windows Vista include: Windows Vista shipped in six different product editions. These were deviced across separate consumer and business target markets, with editions varying in features to cater to specific sub-markets. For consumers, there are three editions, with two available for economically more developed countries. Windows Vista Starter edition

9246-471: The ASCII representation formed a sequence of meaningful characters, such as an abbreviation of the application's name or the developer's initials. For instance a HyperCard "stack" file has a creator of WILD (from Hypercard's previous name, "WildCard") and a type of STAK . The BBEdit text editor has a creator code of R*ch referring to its original programmer, Rich Siegel . The type code specifies

9384-547: The CHS value in the VHD footer does not match the (virtual) CHS geometry in the Master Boot Record of the disk image in the VHD. Microsoft Virtual Server (also Connectix derived) has this limitation using virtual IDE drivers but 2 TiB if virtual RAID or virtual SCSI drivers are used. Virtual Hard Disk format was initially used only by Microsoft Virtual PC (and Microsoft Virtual Server ). Later however, Microsoft used

9522-572: The GeForce FX series on Vista was 96.85. Microsoft offered a tool called the Windows Vista Upgrade Advisor to assist Windows XP and Vista users in determining what versions of Windows their machine is capable of running. The required server connections for this utility are no longer available. Although the installation media included in retail packages is a 32-bit DVD, customers needing a CD-ROM or customers who wish for

9660-471: The Internet around February 28, 2003. It was also privately handed out to a select group of software developers. As an evolutionary release over build 3683, it contained several small improvements, including a modified blue "Plex" theme and a new, simplified Windows Image-based installer that operates in graphical mode from the outset, and completed an install of the operating system in approximately one third

9798-571: The Longhorn project as "another Cairo" or "Cairo.NET", referring to the Cairo development project that the company embarked on through the first half of the 1990s, which never resulted in a shipping operating system (though nearly all the technologies developed in that time did end up in Windows 95 and Windows NT ). Microsoft was shocked in 2005 by Apple's release of Mac OS X Tiger . It offered only

9936-513: The PUID scheme does provide greater granularity than most alternative schemes. MIME types are widely used in many Internet -related applications, and increasingly elsewhere, although their usage for on-disc type information is rare. These consist of a standardised system of identifiers (managed by IANA ) consisting of a type and a sub-type , separated by a slash —for instance, text/html or image/gif . These were originally intended as

10074-479: The VHD . The virtual machine additions in older VPC versions and the virtual machine integration features in Windows Virtual PC contain precompact ISO images for the first step in supported guest systems. Third-party products also use VHD file format. Oracle VirtualBox , part of Sun xVM line of Sun Microsystems supports VHD in versions 2 and later. In 2017 Red Gate Software and Windocks introduced VHD based support for SQL Server database cloning. It

10212-534: The VHD format in Hyper-V , the hypervisor -based virtualization technology of Windows Server 2008 . Microsoft also used the format in Complete PC Backup , a backup software component included with Windows Vista and Windows 7 . In addition, Windows 7 and Windows Server 2008 R2 include support for creating, mounting, and booting from VHD files. The Vista (or later) drive manager GUI supports

10350-483: The VM settings for Generation 1 virtual machines. Generation 2 virtual machines do not emulate a floppy controller and do not support floppy disk images. VHDX (Virtual Hard Disk v2) is the successor format to VHD. Where VHD has a capacity limit of 2040 GB, VHDX has a capacity limit of 64 TB. For disk images with this newer format the filename extension vhdx is used instead of vhd . VHDX protects against power failures and

10488-751: The VSAM catalog (prior to ICF catalogs ) and the VSAM Volume Record in the VSAM Volume Data Set (VVDS) (with ICF catalogs) identifies the type of VSAM dataset. In IBM OS/360 through z/OS , a format 1 or 7 Data Set Control Block (DSCB) in the Volume Table of Contents (VTOC) identifies the Dataset Organization ( DSORG ) of the dataset described by it. The HPFS , FAT12, and FAT16 (but not FAT32) filesystems allow

10626-585: The Windows Aero interface. As of Windows Vista Beta 2, the NVIDIA GeForce 6 series and later, the ATI Radeon 9500 and later, Intel's GMA 950 and later integrated graphics, and a handful of VIA chipsets and S3 Graphics discrete chips are supported. Although originally supported, the GeForce FX 5 series has been dropped from newer drivers from NVIDIA. The last driver from NVIDIA to support

10764-442: The appropriate icons, but these will be located in different places on the storage medium thus taking longer to access. A folder containing many files with complex metadata such as thumbnail information may require considerable time before it can be displayed. If a header is binary hard-coded such that the header itself needs complex interpretation in order to be recognized, especially for metadata content protection's sake, there

10902-627: The audio being received by the speech recognition software being "incredibly distorted". Windows Vista build 5824 (October 17, 2006) was supposed to be the RTM release, but a bug, where the OOBE hangs at the start of the WinSAT Assessment (if upgraded from Windows XP), requiring the user to terminate msoobe.exe by pressing Shift+F10 to open Command Prompt using either command-line tools or Task Manager prevented this, damaging development and lowering

11040-849: The business-oriented versions like Windows 2000 (build 2195) or Server 2003 (build 3790). On November 16, 2006, Microsoft made the final build available to MSDN and Technet Plus subscribers. A business-oriented Enterprise edition was made available to volume license customers on November 30, 2006. Windows Vista was launched for general customer availability on January 30, 2007. New features introduced by Windows Vista are very numerous, encompassing significant functionality not available in its predecessors. Vista includes technologies such as ReadyBoost and ReadyDrive , which employ fast flash memory (located on USB flash drives and hybrid hard disk drives ) to improve system performance by caching commonly used programs and data. This manifests itself in improved battery life on notebook computers as well, since

11178-569: The chance that it would hit its January 2007 deadline. Development of Windows Vista came to an end when Microsoft announced that it had been finalized on November 8, 2006, and was concluded by co-president of Windows development, Jim Allchin . The RTM's build number had also jumped to 6000 to reflect Vista's internal version number, NT 6.0. Jumping RTM build numbers is common practice among consumer-oriented Windows versions, like Windows 98 (build 1998), Windows 98 SE (build 2222), Windows Me (build 3000) or Windows XP (build 2600), as compared to

11316-454: The command interpreter. Another operating system using magic numbers is AmigaOS , where magic numbers were called "Magic Cookies" and were adopted as a standard system to recognize executables in Hunk executable file format and also to let single programs, tools and utilities deal automatically with their saved data files, or any other kind of file types when saving and loading data. This system

11454-431: The computer. The same is true with files with only one extension: as it is not shown to the user, no information about the file can be deduced without explicitly investigating the file. To further trick users, it is possible to store an icon inside the program, in which case some operating systems' icon assignment for the executable file ( .exe ) would be overridden with an icon commonly used to represent JPEG images, making

11592-617: The core of the operating system, notably the completely re-designed audio, networking, print, and video interfaces, major changes to the security infrastructure, improvements to the deployment and installation of applications (" ClickOnce " and Windows Installer 4.0), new device driver development model (" Windows Driver Foundation "), Transactional NTFS , mobile computing API advancements (power management, Tablet PC Ink support, SideShow ) and major updates to (or complete replacements of) many core subsystems such as Winlogon and CAPI . There are some issues for software developers using some of

11730-477: The creator of the driver can be identified. This is also on par with one of the primary goals of Vista to move code out of kernel-mode into user-mode drivers, with another example bing the new Windows Display Driver Model . While much of the focus of Vista's new capabilities highlighted the new user interface, security technologies, and improvements to the core operating system, Microsoft also adding new deployment and maintenance features: Windows Vista includes

11868-419: The data must be entirely parsed by applications. On Unix and Unix-like systems, the ext2 , ext3 , ext4 , ReiserFS version 3, XFS , JFS , FFS , and HFS+ filesystems allow the storage of extended attributes with files. These include an arbitrary list of "name=value" strings, where the names are unique and a value can be accessed through its related name. The PRONOM Persistent Unique Identifier (PUID)

12006-430: The destination, the single file received has to be unzipped by a compatible utility to be useful. The problems of handling metadata are solved this way using zip files or archive files. The Mac OS ' Hierarchical File System stores codes for creator and type as part of the directory entry for each file. These codes are referred to as OSTypes. These codes could be any 4-byte sequence but were often selected so that

12144-461: The end, Microsoft chose Windows Vista as confirmed on July 22, 2005, believing it to be a "wonderful intersection of what the product really does, what Windows stands for, and what resonates with customers, and their needs". Group Project Manager Greg Sullivan told Paul Thurrott "You want the PC to adapt to you and help you cut through the clutter to focus on what's important to you. That's what Windows Vista

12282-435: The file during the loading process and afterwards. File headers may be used by an operating system to quickly gather information about a file without loading it all into memory, but doing so uses more of a computer's resources than reading directly from the directory information. For instance, when a graphic file manager has to display the contents of a folder, it must read the headers of many files before it can display

12420-448: The file format's definition. Throughout the 1970s, many programs used formats of this general kind. For example, word-processors such as troff , Script , and Scribe , and database export files such as CSV . Electronic Arts and Commodore - Amiga also used this type of file format in 1985, with their IFF (Interchange File Format) file format. A container is sometimes called a "chunk" , although "chunk" may also imply that each piece

12558-831: The file, each of which is a string, such as "Plain Text" or "HTML document". Thus a file may have several types. The NTFS filesystem also allows storage of OS/2 extended attributes, as one of the file forks , but this feature is merely present to support the OS/2 subsystem (not present in XP), so the Win32 subsystem treats this information as an opaque block of data and does not use it. Instead, it relies on other file forks to store meta-information in Win32-specific formats. OS/2 extended attributes can still be read and written by Win32 programs, but

12696-483: The first time in Windows, graphics processing unit (GPU) multitasking is possible, enabling users to run more than one GPU-intensive application simultaneously. At the core of the operating system , many improvements have been made to the memory manager, process scheduler and I/O scheduler. The Heap Manager implements additional features such as integrity checking in order to improve robustness and defend against buffer overflow security exploits , although this comes at

12834-471: The format of the file, while the creator code specifies the default program to open it with when double-clicked by the user. For example, the user could have several text files all with the type code of TEXT , but each open in a different program, due to having differing creator codes. This feature was intended so that, for example, human-readable plain-text files could be opened in a general-purpose text editor, while programming or HTML code files would open in

12972-463: The format will be identified correctly, and can often determine more precise information about the file. Since reasonably reliable "magic number" tests can be fairly complex, and each file must effectively be tested against every possibility in the magic database, this approach is relatively inefficient, especially for displaying large lists of files (in contrast, file name and metadata-based methods need to check only one piece of data, and match it against

13110-586: The format's developers for a fee and by signing a non-disclosure agreement . The latter approach is possible only when a formal specification document exists. Both strategies require significant time, money, or both; therefore, file formats with publicly available specifications tend to be supported by more programs. Patent law, rather than copyright , is more often used to protect a file format. Although patents for file formats are not directly permitted under US law, some formats encode data using patented algorithms . For example, prior to 2004, using compression with

13248-479: The graphics APIs in Vista. Games or programs built solely on the Windows Vista-exclusive version of DirectX , version 10, cannot work on prior versions of Windows, as DirectX 10 is not available for previous Windows versions. Also, games that require the features of D3D9Ex, the updated implementation of DirectX 9 in Windows Vista are also incompatible with previous Windows versions. According to

13386-461: The hard disk where they can be loaded into memory very quickly with the least physical movement of the hard disk's read-write heads. As part of the redesign of the networking architecture, IPv6 has been fully incorporated into the operating system and a number of performance improvements have been introduced, such as TCP window scaling . Earlier versions of Windows typically needed third-party wireless networking software to work properly, but this

13524-449: The introduction of many new security and safety features such as BitLocker and User Account Control . The ambitiousness and scope of these changes, and the abundance of new features earned positive reviews, but Windows Vista was the subject of frequent negative press and significant criticism. Criticism of Windows Vista focused on driver, peripheral, and program incompatibility; digital rights management ; excessive authorization from

13662-434: The latest features from every development team at Microsoft was included. Typically, a team working on a certain feature or subsystem would generate their working builds which developers would test with, and when the code was deemed stable, all the changes would be incorporated back into the main development tree at once. At Microsoft, several "Build labs" exist where the compilation of the entirety of Windows can be performed by

13800-515: The main data and the name, but is also less portable than either filename extensions or "magic numbers", since the format has to be converted from filesystem to filesystem. While this is also true to an extent with filename extensions— for instance, for compatibility with MS-DOS 's three character limit— most forms of storage have a roughly equivalent definition of a file's data and name, but may have varying or no representation of further metadata. Note that zip files or archive files solve

13938-514: The market was quickly moving to 64-bit processors. While Microsoft had originally hoped to have the consumer versions of the operating system available worldwide in time for the 2006 holiday shopping season , it announced in March 2006 that the release date would be pushed back to January 2007 in order to give the company—and the hardware and software companies that Microsoft depends on for providing device drivers —additional time to prepare. Because

14076-430: The memory images also have reserved spaces for future extensions, extending and improving this type of structured file is very difficult. It also creates files that might be specific to one platform or programming language (for example a structure containing a Pascal string is not recognized as such in C ). On the other hand, developing tools for reading and writing these types of files is very simple. The limitations of

14214-448: The native host file system. The following types of VHD formats are supported by Microsoft Virtual PC and Virtual Server : Significant benefits result from the ability to boot a physical computer from a virtual hard drive: Native VHD Boot refers to the ability of a physical computer to mount and boot from an operating system contained within a VHD. Windows 7 Enterprise and Ultimate editions support this ability, both with and without

14352-723: The network) cannot interact with parts of the operating system they do not need to. Obfuscation techniques such as address space layout randomization are used to increase the amount of effort required of malware before successful infiltration of a system. Code integrity verifies that system binaries have not been tampered with by malicious code. As part of the redesign of the network stack, Windows Firewall has been upgraded, with new support for filtering both incoming and outgoing traffic. Advanced packet filter rules can be created that can grant or deny communications to specific services. The 64-bit versions of Vista require that all new Kernel-Mode device drivers be digitally signed, so that

14490-536: The new Desktop Window Manager and Aero . The demonstrations were done on a revised build 4015 which was never released. Several sessions for developers and hardware engineers at the conference focused on these new features, as well as the Next-Generation Secure Computing Base (previously known as "Palladium"), which at the time was Microsoft's proposed solution for creating a secure computing environment whereby any given component of

14628-579: The new User Account Control; inordinately high system requirements when contrasted with Windows XP; its protracted development; longer boot time ; and more restrictive product licensing. Windows Vista deployment and satisfaction rates were consequently lower than those of Windows XP, and it is considered a market failure; however, its use surpassed Microsoft's pre-launch two-year-out expectations of achieving 200 million users (with an estimated 330 million users by 2009). On October 22, 2010, Microsoft ceased retail distribution of Windows Vista; OEM supply ceased

14766-413: The new development process and build methodology would be used by all of the development teams. A number of complaints came from individual developers, and Bill Gates himself, that the new development process was going to be prohibitively difficult to work within. By approximately November 2004, the company had considered several names for the final release, ranging from simple to fanciful and inventive. In

14904-442: The only time this partition is accessed is when the computer is booting, or when there is a Windows update that changes files in this area, which is a legitimate reason to access this section of the drive. The area can be a potential security issue, because a hexadecimal editor (such as dskprobe.exe), or malicious software running with administrator and/or kernel level privileges would be able to write to this "Ghost Partition" and allow

15042-471: The planned features for the final product, as well as a number of changes to the user interface, based largely on feedback from beta testers. Windows Vista was deemed feature-complete with the release of the "February CTP", released on February 22, 2006, and much of the remainder of the work between that build and the final release of the product focused on stability, performance, application and driver compatibility, and documentation. Beta 2, released in late May,

15180-406: The price of breaking backward compatibility with some legacy applications. A Kernel Transaction Manager has been implemented that enables applications to work with the file system and Registry using atomic transaction operations. Improved security was a primary design goal for Vista. Microsoft's Trustworthy Computing initiative, which aims to improve public trust in its products, has had

15318-416: The problem of handling metadata. A utility program collects multiple files together along with metadata about each file and the folders/directories they came from all within one new file (e.g. a zip file with extension .zip ). The new file is also compressed and possibly encrypted, but now is transmissible as a single file across operating systems by FTP transmissions or sent by email as an attachment. At

15456-447: The program look like an image. Extensions can also be spoofed: some Microsoft Word macro viruses create a Word file in template format and save it with a .doc extension. Since Word generally ignores extensions and looks at the format of the file, these would open as templates, execute, and spread the virus. This represents a practical problem for Windows systems where extension-hiding is turned on by default. A second way to identify

15594-456: The project in 2004. Many features were eventually reimplemented after the reset, but Microsoft ceased using managed code to develop the operating system. New features of Windows Vista include a graphical user interface and visual style referred to as Windows Aero ; a content index and desktop search platform called Windows Search ; new peer-to-peer technologies to simplify sharing files and media between computers and devices on

15732-819: The same thing as identifiers in the sense of a database key or serial number (although an identifier may well identify its associated data as such a key). With this type of file structure, tools that do not know certain chunk identifiers simply skip those that they do not understand. Depending on the actual meaning of the skipped data, this may or may not be useful ( CSS explicitly defines such behavior). This concept has been used again and again by RIFF (Microsoft-IBM equivalent of IFF), PNG, JPEG storage, DER ( Distinguished Encoding Rules ) encoded streams and files (which were originally described in CCITT X.409:1984 and therefore predate IFF), and Structured Data Exchange Format (SDXF) . Indeed, any data format must somehow identify

15870-544: The security of the Windows codebase, which is programmed in C , C++ and assembly . Longhorn became known as Vista in 2005. Vista in Spanish means view. The early development stages of Longhorn were generally characterized by incremental improvements and updates to Windows XP. During this period, Microsoft was fairly quiet about what was being worked on, as their marketing and public relations efforts were more strongly focused on Windows XP, and Windows Server 2003 , which

16008-545: The significance of its component parts, and embedded boundary-markers are an obvious way to do so: This is another extensible format, that closely resembles a file system ( OLE Documents are actual filesystems), where the file is composed of 'directory entries' that contain the location of the data within the file itself as well as its signatures (and in certain cases its type). Good examples of these types of file structures are disk images , executables , OLE documents TIFF , libraries . Windows Vista Windows Vista

16146-505: The slider was. File metadata was also made more visible and more easily editable, with more active encouragement to fill out missing pieces of information. Also of note was the conversion of Windows Explorer to being a .NET application. Most builds of Longhorn and Vista were identified by a label that was always displayed in the bottom-right corner of the desktop. A typical build label would look like "Longhorn Build 3683.Lab06_N.020923-1821". Higher build numbers did not automatically mean that

16284-401: The software recognized the phrase "Dear mom" as "Dear aunt" . After several failed attempts to correct the error, the sentence eventually became " Dear aunt, let's set so double the killer delete select all ". A developer with Vista's speech recognition team later explained that there was a bug with the build of Vista that was causing the microphone gain level to be set very high, resulting in

16422-586: The standard to which they adhere. Many file types, especially plain-text files, are harder to spot by this method. HTML files, for example, might begin with the string <html> (which is not case sensitive), or an appropriate document type definition that starts with <!DOCTYPE html , or, for XHTML , the XML identifier, which begins with <?xml . The files can also begin with HTML comments, random text, or several empty lines, but still be usable HTML. The magic number approach offers better guarantees that

16560-438: The storage of "extended attributes" with files. These comprise an arbitrary set of triplets with a name, a coded type for the value, and a value, where the names are unique and values can be up to 64 KB long. There are standardized meanings for certain types and names (under OS/2 ). One such is that the ".TYPE" extended attribute is used to determine the file type. Its value comprises a list of one or more file types associated with

16698-404: The system could be deemed "trusted". Also at this conference, Microsoft reiterated their roadmap for delivering Longhorn, pointing to an "early 2005" release date. By 2004, it had become obvious to the Windows team at Microsoft that they were losing sight of what needed to be done to complete the next version of Windows and ship it to customers. Internally, some Microsoft employees were describing

16836-469: The system. This was often difficult in previous versions of Windows, as the previous "limited" user accounts proved too restrictive and incompatible with a large proportion of application software, and even prevented some basic operations such as looking at the calendar from the notification tray. In Windows Vista, when an action is performed that requires administrative rights (such as installing/uninstalling software or making system-wide configuration changes),

16974-460: The time of Windows XP on the same hardware. An optional "new taskbar" was introduced that was thinner than the previous build and displayed the time differently. The most notable visual and functional difference, however, came with Windows Explorer. The incorporation of the Plex theme made blue the dominant color of the entire application. The Windows XP-style task pane was almost completely replaced with

17112-414: The unstructured formats led to the development of other types of file formats that could be easily extended and be backward compatible at the same time. In this kind of file structure, each piece of data is embedded in a container that somehow identifies the data. The container's scope can be identified by start- and end-markers of some kind, by an explicit length field somewhere, or by fixed requirements of

17250-472: The use of this standard awkward in some cases. File format identifiers are another, not widely used way to identify file formats according to their origin and their file category. It was created for the Description Explorer suite of software. It is composed of several digits of the form NNNNNNNNN-XX-YYYYYYY . The first part indicates the organization origin/maintainer (this number represents

17388-510: The user gives consent. Whereas prior releases of Windows supported per-file encryption using Encrypting File System , the Enterprise and Ultimate editions of Vista include BitLocker Drive Encryption , which can protect entire volumes , notably the operating system volume. However, BitLocker requires approximately a 1.5-gigabyte partition to be permanently not encrypted and to contain system files for Windows to boot. In normal circumstances,

17526-401: The user is first prompted for an administrator name and password; in cases where the user is already an administrator, the user is still prompted to confirm the pending privileged action. Regular use of the computer such as running programs, printing, or surfing the Internet does not trigger UAC prompts. User Account Control asks for credentials in a Secure Desktop mode, in which the entire screen

17664-590: Was created by Connectix for their Virtual PC product, known as Microsoft Virtual PC since Microsoft acquired Connectix in 2003. VHDX was introduced in Windows 8/Windows Server 2012 to add features and flexibility missing in VHD that had become apparent over time. Since June 2005, Microsoft has made the VHD and VHDX Image Format Specifications available to third parties under the Microsoft Open Specification Promise . A Virtual Hard Disk allows multiple operating systems to reside on

17802-513: Was executed on a default Windows Vista installation within a standard user account. UAC effectively blocked over 50 percent of each threat , excluding rootkits. 5 percent or less of the malware that evaded UAC survived a reboot. Internet Explorer 7 's new security and safety features include a phishing filter, IDN with anti-spoofing capabilities, and integration with system-wide parental controls. For added security, ActiveX controls are disabled by default. Also, Internet Explorer operates in

17940-583: Was named Windows Vista in July 2005, an unprecedented beta-test program was started, involving hundreds of thousands of volunteers and companies. In September of that year, Microsoft started releasing regular Community Technology Previews (CTP) to beta testers from July 2005 to February 2006. The first of these was distributed at the 2005 Microsoft Professional Developers Conference , and was subsequently released to beta testers and Microsoft Developer Network subscribers. The builds that followed incorporated most of

18078-483: Was not completed until early 2006, and at the time of Microsoft's announcement, no firmware manufacturers had completed a production implementation which could be used for testing. As a result, the decision was made to postpone the introduction of UEFI support to Windows; support for UEFI on 64-bit platforms was postponed until Vista Service Pack 1 and Windows Server 2008 and 32-bit UEFI would not be supported, as Microsoft did not expect many such systems to be built because

18216-709: Was planned to be the company's next major operating system release. Gradually, "Longhorn" assimilated many of the important new features and technologies slated for Blackcomb, resulting in the release date being pushed back several times in three years. In some builds of Longhorn, their license agreement said "For the Microsoft product codenamed 'Whistler'". Many of Microsoft's developers were also re-tasked to build updates to Windows XP and Windows Server 2003 to strengthen security. Faced with ongoing delays and concerns about feature creep , Microsoft announced on August 27, 2004, that it had revised its plans. For this reason, Longhorn

18354-521: Was released in April 2003. Occasional builds of Longhorn were leaked onto popular file sharing networks such as IRC , BitTorrent , eDonkey and various newsgroups , and so most of what is known about builds before the first sanctioned development release of Longhorn in May 2003 is derived from these builds. After several months of relatively little news or activity from Microsoft with Longhorn, Microsoft released Build 4008, which had made an appearance on

18492-543: Was released internationally and was made available for purchase and download from the Windows Marketplace ; it is the first release of Windows to be made available through a digital distribution platform . Development of Windows Vista began in 2001 under the codename "Longhorn"; originally envisioned as a minor successor to Windows XP, it gradually included numerous new features from the then-next major release of Windows codenamed "Blackcomb", after which it

18630-522: Was repositioned as a major release of Windows, and it subsequently underwent a period of protracted development that was unprecedented for Microsoft. Most new features were prominently based on a new presentation layer codenamed Avalon , a new communications architecture codenamed Indigo , and a relational storage platform codenamed WinFS — all built on the .NET Framework ; however, this proved to be untenable due to incompleteness of technologies and ways in which new features were added, and Microsoft reset

18768-497: Was reset to start work on componentizing the Windows Server 2003 Service Pack 1 codebase, and over time re-incorporating the features that would be intended for an actual operating system release. However, some previously announced features such as WinFS were dropped or postponed, and a new software development methodology called the Security Development Lifecycle was incorporated to address concerns with

18906-524: Was the first build to be made available to the general public through Microsoft's Customer Preview Program. It was downloaded over 5 million times. Two release candidates followed in September and October, both of which were made available to a large number of users. At the Intel Developer Forum on March 9, 2006, Microsoft announced a change in their plans to support EFI in Windows Vista. The UEFI 2.0 specification (which replaced EFI 1.10)

19044-579: Was then enhanced with the Amiga standard Datatype recognition system. Another method was the FourCC method, originating in OSType on Macintosh, later adapted by Interchange File Format (IFF) and derivatives. A final way of storing the format of a file is to explicitly store information about the format in the file system, rather than within the file itself. This approach keeps the metadata separate from both

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