138-442: Windows 95 is a consumer-oriented operating system developed by Microsoft as part of its Windows 9x family of operating systems. The first operating system in the 9x family, it is the successor to Windows 3.1 , and was released to manufacturing on July 14, 1995, and generally to retail on August 24, 1995, almost three months after the release of Windows NT 3.51 . Windows 95 is the first version of Microsoft Windows to include
276-638: A CD-ROM that it sent to MSN subscribers in the fall of 1996. When inserted, the CD-ROM opened to the ambitious and flashy 'MSN Preview', an interactive video-based experience that introduced current and prospective subscribers to the new version of MSN and described the features of the MSN 2.0 software. The MSN Preview was filmed at the Paramount Theatre in Seattle and was formatted as a guided tour of
414-417: A mock premiere event for the new MSN. It was hosted by a witty and sarcastic character named 'Michael' who welcomed viewers outside of the theater and then guided them through the theater to meet several other characters, each of whom represented one of the channels of MSN 2.0's 'On Stage' area, the main platform for interactive multimedia content in MSN 2.0. A handful of uncredited actors appeared in
552-428: A system call to perform a block I/O write operation, then the system call might execute the following instructions: While the writing takes place, the operating system will context switch to other processes as normal. When the device finishes writing, the device will interrupt the currently running process by asserting an interrupt request . The device will also place an integer onto the data bus. Upon accepting
690-645: A computer even if they are not compatible with the base operating system. A library operating system (libOS) is one in which the services that a typical operating system provides, such as networking, are provided in the form of libraries and composed with a single application and configuration code to construct a unikernel : a specialized (only the absolute necessary pieces of code are extracted from libraries and bound together ), single address space , machine image that can be deployed to cloud or embedded environments. The operating system code and application code are not executed in separated protection domains (there
828-554: A consequence of DOS compatibility, Windows 95 has to keep internal DOS data structures synchronized with those of Windows 95. When starting a program, even a native 32-bit Windows program, MS-DOS momentarily executes to create a data structure known as the Program Segment Prefix . It is even possible for MS-DOS to run out of conventional memory while doing so, preventing the program from launching. Windows 3.x allocated fixed segments in conventional memory first. Since
966-483: A detailed document for media reviewers describing the new system highlights. The preview versions expired in November 1995, after which the user would have to purchase their copy of the final version of Windows 95. Windows 95 was designed to be maximally compatible with existing MS-DOS and 16-bit Windows programs and device drivers while offering a more stable and better performing system. The Windows 95 architecture
1104-585: A development of MULTICS for a single user. Because UNIX's source code was available, it became the basis of other, incompatible operating systems, of which the most successful were AT&T 's System V and the University of California 's Berkeley Software Distribution (BSD). To increase compatibility, the IEEE released the POSIX standard for operating system application programming interfaces (APIs), which
1242-484: A large legal settlement was paid. In the twenty-first century, Windows continues to be popular on personal computers but has less market share of servers. UNIX operating systems, especially Linux, are the most popular on enterprise systems and servers but are also used on mobile devices and many other computer systems. On mobile devices, Symbian OS was dominant at first, being usurped by BlackBerry OS (introduced 2002) and iOS for iPhones (from 2007). Later on,
1380-668: A large quantity of point-of-sale material; many branches opened at midnight to sell the first copies of the product. Copies of The Times were available for free, and Microsoft paid for 1.5 million issues (twice the daily circulation at the time). In the United States, the Empire State Building in New York City was lit to match the colors of the Windows logo. In Canada, a 100 m (330 ft) banner
1518-442: A library with no protection between applications, such as eCos . A hypervisor is an operating system that runs a virtual machine . The virtual machine is unaware that it is an application and operates as if it had its own hardware. Virtual machines can be paused, saved, and resumed, making them useful for operating systems research, development, and debugging. They also enhance portability by enabling applications to be run on
SECTION 10
#17327718391001656-420: A mainly cooperatively multitasked 16-bit architecture to a 32-bit preemptive multitasking architecture, at least when running only 32-bit protected mode applications. Accompanied by an extensive marketing campaign, Windows 95 introduced numerous functions and features that were featured in later Windows versions, and continue in modern variations to this day, such as the taskbar , notification area , and
1794-447: A malformed machine instruction . However, the most common error conditions are division by zero and accessing an invalid memory address . Users can send messages to the kernel to modify the behavior of a currently running process. For example, in the command-line environment , pressing the interrupt character (usually Control-C ) might terminate the currently running process. To generate software interrupts for x86 CPUs,
1932-425: A new program known as the 'MSN Program Viewer.' The service was promoted to existing MSN subscribers beginning October 10, 1996; the general release followed on December 10, 1996. Microsoft promoted MSN 2.0 with a series of advertisements and promotional materials describing the service with the phrase, "Every new universe begins with a big bang." The company offered the initial release of the new MSN 2.0 service on
2070-455: A particular application's memory is stored, or even whether or not it has been allocated yet. In modern operating systems, memory which is accessed less frequently can be temporarily stored on a disk or other media to make that space available for use by other programs. This is called swapping , as an area of memory can be used by multiple programs, and what that memory area contains can be swapped or exchanged on demand. Virtual memory provides
2208-404: A partnership between Microsoft and NBC ; and Slate , an online magazine focused on politics and current events. Both websites were available to all Internet users and still exist today, although they are no longer owned by Microsoft. Also integrated into MSN 2.0 shortly after its launch was Microsoft's popular Internet Gaming Zone , which later became MSN Games . Interactive multimedia content
2346-469: A program called MSN Explorer. This program is similar to the early MSN Program Viewer in that it provides access to MSN websites, email , instant messaging , and other content on top of a web browser (an Internet Explorer shell ) based on the Trident layout engine . MSN Explorer is similar to AOL Desktop , which also has a built-in email client and provides access to content for AOL members. Upon
2484-503: A program does not interfere with memory already in use by another program. Since programs time share, each program must have independent access to memory. Cooperative memory management, used by many early operating systems, assumes that all programs make voluntary use of the kernel 's memory manager, and do not exceed their allocated memory. This system of memory management is almost never seen any more, since programs often contain bugs which can cause them to exceed their allocated memory. If
2622-408: A program fails, it may cause memory used by one or more other programs to be affected or overwritten. Malicious programs or viruses may purposefully alter another program's memory, or may affect the operation of the operating system itself. With cooperative memory management, it takes only one misbehaved program to crash the system. Memory protection enables the kernel to limit a process' access to
2760-440: A program tries to access memory that is not accessible memory, but nonetheless has been allocated to it, the kernel is interrupted (see § Memory management ) . This kind of interrupt is typically a page fault . When the kernel detects a page fault it generally adjusts the virtual memory range of the program which triggered it, granting it access to the memory requested. This gives the kernel discretionary power over where
2898-490: A rumour spread by the band to increase their market value, and the company paid US$ 3 million. A 30-minute promotional video, labeled a "cyber sitcom," featuring Jennifer Aniston and Matthew Perry , was also released to showcase the features of Windows 95. Microsoft's US$ 200 million advertising campaign featured stories of people waiting in line outside stores to get a copy. In the UK, the largest computer chain, PC World , received
SECTION 20
#17327718391003036-470: A significant amount of CPU time. Direct memory access (DMA) is an architecture feature to allow devices to bypass the CPU and access main memory directly. (Separate from the architecture, a device may perform direct memory access to and from main memory either directly or via a bus.) When a computer user types a key on the keyboard, typically the character appears immediately on the screen. Likewise, when
3174-468: A special name like Metro , Aqua or Material Design . Internally it was called "the new shell" and later simply "the shell". The subproject within Microsoft to develop the new shell was internally known as "Stimpy". In 1994, Microsoft designers Mark Malamud and Erik Gavriluk approached Brian Eno to compose music for the Windows 95 project. The result was the six-second start-up music-sound of
3312-402: A specific moment in time. Hard real-time systems require exact timing and are common in manufacturing , avionics , military, and other similar uses. With soft real-time systems, the occasional missed event is acceptable; this category often includes audio or multimedia systems, as well as smartphones. In order for hard real-time systems be sufficiently exact in their timing, often they are just
3450-417: A user moves a mouse , the cursor immediately moves across the screen. Each keystroke and mouse movement generates an interrupt called Interrupt-driven I/O . An interrupt-driven I/O occurs when a process causes an interrupt for every character or word transmitted. Devices such as hard disk drives , solid-state drives , and magnetic tape drives can transfer data at a rate high enough that interrupting
3588-702: A user to fix problems relating to loading native, protected-mode drivers. OEM Service Releases of Windows 95 introduced support in Windows for several core new technologies that were not included in the original release of Windows 95. These include the Internet Explorer web browser, DriveSpace compression, OpenGL , DirectX , FAT32 file system support, UltraDMA mode for disk drives, Universal Serial Bus , IEEE 1394 (FireWire) , and Accelerated Graphics Port . Windows 95 introduced computer accessibility features like Sticky keys , FilterKeys , ToggleKeys , Mouse keys . Microsoft Active Accessibility API
3726-453: A variation of the classic reader/writer problem . The writer receives a pipe from the shell for its output to be sent to the reader's input stream. The command-line syntax is alpha | bravo . alpha will write to the pipe when its computation is ready and then sleep in the wait queue. bravo will then be moved to the ready queue and soon will read from its input stream. The kernel will generate software interrupts to coordinate
3864-463: A volume control and the current time. The Start menu , invoked by clicking the "Start" button on the taskbar or by pressing the Windows key , was introduced as an additional means of launching applications or opening documents. While maintaining the program groups used by its predecessor Program Manager , it also displayed applications within cascading sub-menus. The previous File Manager program
4002-697: A year in the U.S., also costing 99 euros in European countries like Germany and France. In the past, Premium could be obtained by American customers by acquiring DSL through one of MSN's partners, such as Verizon or Qwest (now merged with CenturyLink ) in the United States or Bell Internet in Canada . Microsoft also offered premium services with Verizon through the Windows Live brand name beginning in 2006. MSN Premium provided through Verizon
4140-562: Is remote direct memory access , which enables each CPU to access memory belonging to other CPUs. Multicomputer operating systems often support remote procedure calls where a CPU can call a procedure on another CPU, or distributed shared memory , in which the operating system uses virtualization to generate shared memory that does not physically exist. A distributed system is a group of distinct, networked computers—each of which might have their own operating system and file system. Unlike multicomputers, they may be dispersed anywhere in
4278-428: Is system software that manages computer hardware and software resources, and provides common services for computer programs . Time-sharing operating systems schedule tasks for efficient use of the system and may also include accounting software for cost allocation of processor time , mass storage , peripherals, and other resources. For hardware functions such as input and output and memory allocation ,
Windows 95 - Misplaced Pages Continue
4416-490: Is a subscription service provided by Microsoft that combines a number of different Internet services , along with firewall and anti-virus software provided by McAfee and Spy Sweeper , into a premium version of MSN Explorer. In order to use MSN Premium, users subscribe to the service through get.msn.com. Alternatively, MSN Premium can be purchased directly from the Microsoft Store and (as of 2022) costs $ 99 for
4554-484: Is a change away from the currently running process. Similarly, both hardware and software interrupts execute an interrupt service routine . Software interrupts may be normally occurring events. It is expected that a time slice will occur, so the kernel will have to perform a context switch . A computer program may set a timer to go off after a few seconds in case too much data causes an algorithm to take too long. Software interrupts may be error conditions, such as
4692-589: Is an evolution of Windows for Workgroups ' 386 enhanced mode. Access requests to physical media are sent to Input/Output Supervisor , a component responsible for scheduling the requests. Each physical media has its device driver: access to the disk is performed by a port driver , while access to a SCSI device is handled by a miniport driver working atop the SCSI layer. Port and Miniport drivers perform I/O operations in 32-bit protected mode, bypassing MS-DOS and BIOS , significantly improving performance. In case there
4830-745: Is capable of using all 16-bit Windows 3.x drivers. Unlike Windows 3.x, DOS programs running in Windows 95 do not need DOS drivers for the mouse, CD-ROM and sound card; Windows drivers are used instead. HIMEM.SYS is still required to boot Windows 95. EMM386 and other memory managers, however, are only used by DOS programs. In addition, CONFIG.SYS and AUTOEXEC.BAT settings (aside from HIMEM.SYS) do not affect Windows programs. DOS games, which could not be executed on Windows 3.x, can run inside Windows 95 (games tended to lock up Windows 3.x or cause other problems). As with Windows 3.x, DOS programs that use EGA or VGA graphics modes run in windowed mode ( CGA and text mode programs can continue to run). On startup,
4968-422: Is difficult to define, but has been called "the layer of software that manages a computer's resources for its users and their applications ". Operating systems include the software that is always running, called a kernel —but can include other software as well. The two other types of programs that can run on a computer are system programs —which are associated with the operating system, but may not be part of
5106-521: Is locked out. In case the need arises to depend on disk utilities that do not recognize long file names, such as the MS-DOS 6.x's defrag utility, a program called LFNBACK for backup and restoration of long file names is provided on the CD-ROM, specifically in its \ADMIN\APPTOOLS\LFNBACK directory. Windows 95 followed Windows for Workgroups 3.11 with its lack of support for older, 16-bit x86 processors, thus requiring an Intel 80386 (or compatible). While
5244-568: Is necessary for the long file names feature introduced with Windows 95 through the use of the VFAT file system extension. It is available to both Windows programs and MS-DOS programs started from Windows (they have to be adapted slightly, since accessing long file names requires using larger pathname buffers and hence different system calls ). Competing DOS-compatible operating systems released before Windows 95 cannot see these names. Using older versions of DOS utilities to manipulate files means that
5382-517: Is no native Windows driver for a certain storage device, or if a device is forced to run in compatibility mode, the Real Mode Mapper can access it through MS-DOS. 32-bit Windows programs are assigned their memory segments, which can be adjusted to any desired size. Memory areas outside the segment cannot be accessed by a program. If a program crashes, nothing else is harmed. Before this, programs used fixed non-exclusive 64 KB segments. While
5520-513: Is often no longer used for managing hard disks. DOS can be used for running old-style drivers for compatibility, but Microsoft discourages using them, as this prevents proper multitasking and impairs system stability. Control Panel allows a user to see which MS-DOS components are used by the system; optimal performance is achieved when they are bypassed. The Windows kernel uses MS-DOS style real-mode drivers in Safe Mode , which exists to allow
5658-443: Is only a single application running, at least conceptually, so there is no need to prevent interference between applications) and OS services are accessed via simple library calls (potentially inlining them based on compiler thresholds), without the usual overhead of context switches , in a way similarly to embedded and real-time OSes. Note that this overhead is not negligible: to the direct cost of mode switching it's necessary to add
Windows 95 - Misplaced Pages Continue
5796-536: Is possible to prevent the loading of the graphical user interface and boot the system into a real-mode MS-DOS environment. This was done by inserting command.com into the autoexec.bat file or changing the BootGUI variable in the MSDOS.SYS file to 0. This sparked debate amongst users and professionals regarding the extent to which Windows 95 is an operating system or merely a graphical shell running on top of MS-DOS. When
5934-499: Is supported by most UNIX systems. MINIX was a stripped-down version of UNIX, developed in 1987 for educational uses, that inspired the commercially available, free software Linux . Since 2008, MINIX is used in controllers of most Intel microchips , while Linux is widespread in data centers and Android smartphones. The invention of large scale integration enabled the production of personal computers (initially called microcomputers ) from around 1980. For around five years,
6072-473: Is that they do not load user-installed software. Consequently, they do not need protection between different applications, enabling simpler designs. Very small operating systems might run in less than 10 kilobytes , and the smallest are for smart cards . Examples include Embedded Linux , QNX , VxWorks , and the extra-small systems RIOT and TinyOS . A real-time operating system is an operating system that guarantees to process events or data by or at
6210-435: Is the part of the operating system that provides protection between different applications and users. This protection is key to improving reliability by keeping errors isolated to one program, as well as security by limiting the power of malicious software and protecting private data, and ensuring that one program cannot monopolize the computer's resources. Most operating systems have two modes of operation: in user mode ,
6348-514: The .NET Framework , versions 2.0 and 3.5 were unofficially backported for the operating system in 2024. Windows 95 originally shipped without Internet Explorer , and the default network installation did not include TCP/IP , the network protocol used on the Internet. At the release date of Windows 95, Internet Explorer 1.0 was available, but only in the Plus! add-on pack for Windows 95, which
6486-542: The CP/M (Control Program for Microcomputers) was the most popular operating system for microcomputers. Later, IBM bought the DOS (Disk Operating System) from Microsoft . After modifications requested by IBM, the resulting system was called MS-DOS (MicroSoft Disk Operating System) and was widely used on IBM microcomputers. Later versions increased their sophistication, in part by borrowing features from UNIX. Apple 's Macintosh
6624-504: The INT assembly language instruction is available. The syntax is INT X , where X is the offset number (in hexadecimal format) to the interrupt vector table . To generate software interrupts in Unix-like operating systems, the kill(pid,signum) system call will send a signal to another process. pid is the process identifier of the receiving process. signum is
6762-493: The MSN Messenger Service for instant messaging was launched in 1999. Unlike the 'Friends Online' service bundled with MSN 2.5 that required an MSN membership, anyone with a free Microsoft Passport or Hotmail account could use MSN Messenger. With the release of Windows XP in 2001 (which also brought with it Internet Explorer 6 .0), Microsoft began to offer content for MSN Internet Access subscribers through
6900-551: The Windows Desktop Update . The CD version of the last release of Windows 95, OEM Service Release 2.5 (version 4.00.950C), includes Internet Explorer 4, and installs it after Windows 95's initial setup and first boot are complete. While only the 4.x series of the browser contained the option to install the Windows Desktop Update features, the subsequent 5.x version had the option hidden. Editing
7038-498: The personal computer market, as of September 2024 , Microsoft Windows holds a dominant market share of around 73%. macOS by Apple Inc. is in second place (15%), Linux is in third place (5%), and ChromeOS is in fourth place (2%). In the mobile sector (including smartphones and tablets ), as of September 2023 , Android's share is 68.92%, followed by Apple's iOS and iPadOS with 30.42%, and other operating systems with .66%. Linux distributions are dominant in
SECTION 50
#17327718391007176-420: The transistor in the mid-1950s, mainframes began to be built. These still needed professional operators who manually do what a modern operating system would do, such as scheduling programs to run, but mainframes still had rudimentary operating systems such as Fortran Monitor System (FMS) and IBSYS . In the 1960s, IBM introduced the first series of intercompatible computers ( System/360 ). All of them ran
7314-735: The "Start" button which summons the Start menu . It is considered to be one of the biggest and most important products in the personal computing industry. Three years after its introduction, Windows 95 was followed by Windows 98 . Nevertheless, Windows 95 remained the most popular operating system in 1998, despite the release of Windows 98. Microsoft ended mainstream support for Windows 95 on December 31, 2000. Like Windows NT 3.51 , Windows 95 received only one year of extended support, ending on December 31, 2001. The initial design and planning of Windows 95 can be traced back to around March 1992, just around
7452-501: The 64 KB size was a serious handicap in DOS and Windows 3.x, lack of guarantee of exclusiveness was the cause of stability issues because programs sometimes overwrote each other's segments. A crashing Windows 3.x program could knock out surrounding processes. The Win32 API is implemented by three modules, each consisting of a 16-bit and a 32-bit component: To end-users, MS-DOS appears as an underlying component of Windows 95. For example, it
7590-640: The CD-ROM version might have featured. Microsoft Plus! for Windows 95 was also available on floppy disks. Windows 95 was superseded by Windows 98 , which also included the Windows Desktop Update and Internet Explorer 4 by default. It could still be directly upgraded by either Windows 2000 Professional or Windows Me . Office 2000 was the last version of Microsoft Office to be compatible with Windows 95. Similarly, Windows Media Player 7.0, released in June 2000, and DirectX 8.0a, released in February 2001, are
7728-410: The CPU for every byte or word transferred, and having the CPU transfer the byte or word between the device and memory, would require too much CPU time. Data is, instead, transferred between the device and memory independently of the CPU by hardware such as a channel or a direct memory access controller; an interrupt is delivered only when all the data is transferred. If a computer program executes
7866-474: The CPU to re-enter supervisor mode , placing the kernel in charge. This is called a segmentation violation or Seg-V for short, and since it is both difficult to assign a meaningful result to such an operation, and because it is usually a sign of a misbehaving program, the kernel generally resorts to terminating the offending program, and reports the error. Windows versions 3.1 through ME had some level of memory protection, but programs could easily circumvent
8004-537: The Internet during 1996 and 1997 proved to be ahead of its time, and the MSN 2.0 service was not as successful as Microsoft initially hoped. The company returned to the drawing board for its next MSN release. In 1997, after abandoning the interactive multimedia format, the MSN service was again refocused, this time as a more traditional Internet access service. With the release of MSN 2.5 ( code named 'Metro' and sometimes referred to in marketing materials as 'MSN Premier') in late 1997, some exclusive MSN branded content
8142-400: The MS-DOS component in Windows 95 responds to a pressed F8 key by temporarily pausing the default boot process and presenting the DOS boot options menu, allowing the user to continue starting Windows normally, start Windows in safe mode or exit to the DOS prompt. As in previous versions of MS-DOS , there is no 32-bit support and DOS drivers must be loaded for mice and other hardware. As
8280-533: The MSN Parental Controls menu options with links to the newer Windows Live Family Safety feature. Microsoft began rolling out MSN version 10 in November 2009, following the release of Windows 7 . Features included full compatibility with Internet Explorer 8 , an integrated spell checker, and the ability to exclude MSN Messenger from the installation. Version 10.2 was released in 2011, including photo email integration with SkyDrive (now OneDrive ),
8418-530: The MSN Preview, including then-unknown actress Anna Faris , who represented 'Channel 5', which was described as " media , zines , attitude "; it was targeted at Generation X and college -age members. The preview also included its own jazz and pop music loop that played during the installation process. Once installed, members accessed MSN content through the MSN Program Viewer, which
SECTION 60
#17327718391008556-528: The MSN shows approach was unique and innovative, the content was not easily accessible by members with low-end computers and slower dial-up connections. High-speed Internet access was not widely available at the time, and some users subscribed to monthly dial-up plans that limited the number of hours during which they were allowed to access the service. The MSN 2.0 software was also unstable and would often quit unexpectedly. In addition to MSN 2.0's speed and stability issues, existing MSN subscribers were concerned
8694-474: The Modern Windows Feel (Taskbar, Start Menu.) Windows 95 merged Microsoft's formerly separate MS-DOS and Microsoft Windows products, and featured significant improvements over its predecessor, most notably in the graphical user interface (GUI) and in its simplified " plug-and-play " features. There were also major changes made to the core components of the operating system, such as moving from
8832-505: The OS kernel is 32-bit, much code (especially for the user interface) remained 16-bit for performance reasons as well as development time constraints. The introduction of 32-bit file access in Windows for Workgroups 3.11 meant that 16-bit real mode MS-DOS is not used for managing the files while Windows is running, and the earlier introduction of the 32-bit disk access means that the PC BIOS
8970-503: The Windows 95 Preview Program. For US$ 19.95/£19.95, users would receive several 3.5-inch floppy disks that would be used to install Windows 95 either as an upgrade from Windows 3.1 or as a fresh installation. Participants were also given a free preview of The Microsoft Network (MSN) , the online service that Microsoft launched with Windows 95. During the preview period, Microsoft established various electronic distribution points for promotional and technical documentation on Chicago, including
9108-582: The Windows 95 operating system, The Microsoft Sound and it was first released as a startup sound in May 1995 on Windows 95 May Test Release build 468. When released for Windows 95 and Windows NT 4.0, Internet Explorer 4 came with an optional Windows Desktop Update , which modified the shell to provide several additional updates to Windows Explorer, including a Quick Launch toolbar, and new features integrated with Internet Explorer, such as Active Desktop (which allowed Internet content to be displayed directly on
9246-418: The ability to include photos or a photo slideshow with a link so others can download a copy for themselves, and customizable toolbar button groups. Version 10.5 added minor improvements to the MSN software; most notably Microsoft changed its user agent to disguise it as a newer web browser in order to bypass 'outdated browser' warning messages from some websites. MSN Explorer 11 is the current version, which
9384-538: The application program, which then interacts with the user and with hardware devices. However, in some systems an application can request that the operating system execute another application within the same process, either as a subroutine or in a separate thread, e.g., the LINK and ATTACH facilities of OS/360 and successors . An interrupt (also known as an abort , exception , fault , signal , or trap ) provides an efficient way for most operating systems to react to
9522-514: The basis for the next version of Windows, code named "Chicago." Cairo would be Microsoft's next-generation operating system based on Windows NT, featuring a new user interface and an object-based file system, but it was not planned to be shipped before 1994. Cairo would never be shipped, however, although elements from the Cairo project eventually shipped in Windows NT 4.0 in late July 1996, without
9660-453: The computer's memory. Various methods of memory protection exist, including memory segmentation and paging . All methods require some level of hardware support (such as the 80286 MMU), which does not exist in all computers. In both segmentation and paging, certain protected mode registers specify to the CPU what memory address it should allow a running program to access. Attempts to access other addresses trigger an interrupt, which causes
9798-411: The desktop was re-purposed to hold shortcuts to applications, files and folders, reminiscent of Mac OS . In Windows 3.1 , the desktop was used to display icons of running applications. In Windows 95, the currently running applications were displayed as buttons on a taskbar across the bottom of the screen. The taskbar also contained a notification area used to display icons for background applications,
9936-569: The desktop). Some of the user interface elements introduced in Windows 95, such as the desktop, taskbar, Start menu and Windows Explorer file manager, remained fundamentally unchanged on future versions of Windows. Windows 95 included support for 255-character mixed-case long filenames and preemptively multitasked protected-mode 32-bit applications. 16-bit processes were still co-operatively multitasked. Windows 95 tried to automate device detection and configuration as much as possible, but could still fall back to manual settings if necessary. During
10074-471: The details of how interrupt service routines behave vary from operating system to operating system. However, several interrupt functions are common. The architecture and operating system must: A software interrupt is a message to a process that an event has occurred. This contrasts with a hardware interrupt — which is a message to the central processing unit (CPU) that an event has occurred. Software interrupts are similar to hardware interrupts — there
10212-411: The end of 1998, Windows 95 was the most used desktop OS with 57.4% of the marketshare, with its successor Windows 98 coming in second at 17.2%. Windows 95 also still sold more non- OEM copies to large customers in the month of May 1999, which analysts attributed to large companies opting to wait for the release of Windows 2000 . Several Windows 95 editions have been released. Only the original release
10350-422: The environment. Interrupts cause the central processing unit (CPU) to have a control flow change away from the currently running program to an interrupt handler , also known as an interrupt service routine (ISR). An interrupt service routine may cause the central processing unit (CPU) to have a context switch . The details of how a computer processes an interrupt vary from architecture to architecture, and
10488-423: The file cache size or the size of video memory can help. The theoretical maximum according to Microsoft is 2 GB. Most copies of Windows 95 were on CD-ROM , but a 3 + 1 ⁄ 2 -inch floppy version was also available for older machines. The retail floppy disk version of Windows 95 came on 13 DMF formatted floppy disks, while OSR2.1 doubled the floppy count to 26. Both versions exclude additional software that
10626-567: The graphical user interface is started, the virtual machine manager takes over the filesystem-related and disk-related functionality. MS-DOS itself is demoted to a compatibility layer for 16-bit device drivers. This contrasts with earlier versions of Windows which rely on MS-DOS to perform file and disk access (Windows for Workgroups 3.11 could also largely bypass MS-DOS when 32-bit file access and 32-bit disk access were enabled). Keeping MS-DOS in memory allows Windows 95 to use DOS device drivers when suitable Windows drivers are unavailable. Windows 95
10764-410: The hardware checks that the software is only executing legal instructions, whereas the kernel has unrestricted powers and is not subject to these checks. The kernel also manages memory for other processes and controls access to input/output devices. The operating system provides an interface between an application program and the computer hardware, so that an application program can interact with
10902-493: The hardware only by obeying rules and procedures programmed into the operating system. The operating system is also a set of services which simplify development and execution of application programs. Executing an application program typically involves the creation of a process by the operating system kernel , which assigns memory space and other resources, establishes a priority for the process in multi-tasking systems, loads program binary code into memory, and initiates execution of
11040-418: The indirect pollution of important processor structures (like CPU caches , the instruction pipeline , and so on) which affects both user-mode and kernel-mode performance. The first computers in the late 1940s and 1950s were directly programmed either with plugboards or with machine code inputted on media such as punch cards , without programming languages or operating systems. After the introduction of
11178-656: The initial install process of Windows 95, it would attempt to automatically detect all devices installed in the system. Windows 95 also introduced the Device Manager to indicate which devices were working optimally with correct drivers and configuration and to allow the user to override automatic Plug and Play-based driver installation with manual options or give a choice of several semi-automatic configurations to try to free up resources for devices that still needed manual configuration. Windows 95 also has built-in support for Advanced Power Management . 32-bit File Access
11316-605: The installer's configuration file located in a temporary folder would make the feature available in the installer. Alternatively, Windows 95 and Windows NT 4.0 users could first install IE 4 with the desktop update before installing a newer version of Internet Explorer. The last version of Internet Explorer supported on Windows 95 is Internet Explorer 5.5 with SP2 , which was released on July 23, 2001. Windows 95 shipped with Microsoft's dial-up online service called The Microsoft Network (MSN) . Sales were projected as high as $ 720 million on release day. The marketing campaign for Windows 95
11454-404: The interrupt request, the operating system will: When the writing process has its time slice expired, the operating system will: With the program counter now reset, the interrupted process will resume its time slice. Among other things, a multiprogramming operating system kernel must be responsible for managing all system memory which is currently in use by the programs. This ensures that
11592-417: The introduction of Internet Explorer 4.0 . MSN also launched 'Friends Online', a predecessor to the MSN Messenger Service that allowed members to add each other as friends, see each other's online presence and send instant messages to one another. Accompanying the MSN Program Viewer in MSN 2.5 was 'MSN Quick Launch', an icon inside the Windows notification area . Like the MSN Program Viewer in MSN 2.0,
11730-431: The kernel—and applications—all other software. There are three main purposes that an operating system fulfills: With multiprocessors multiple CPUs share memory. A multicomputer or cluster computer has multiple CPUs, each of which has its own memory . Multicomputers were developed because large multiprocessors are difficult to engineer and prohibitively expensive; they are universal in cloud computing because of
11868-564: The last versions of Windows Media Player and DirectX available for Windows 95, respectively. Updates for Windows 95 could be installed via the Windows Update website. The Windows Update website for Windows 95 and 98 was removed in 2011. An independent project named Windows Update Restored aims to restore the Windows Update websites for older versions of Windows, including Windows 95. While Windows 95 did not officially support
12006-408: The long names are not visible and are lost if files are moved or renamed and by the copy (but not the original) if the file is copied. During a Windows 95 automatic upgrade of an older Windows 3.1 system, DOS and third-party disk utilities which can destroy long file names are identified and made unavailable. When Windows 95 is started in DOS mode, e.g. for running DOS programs, low-level access to disks
12144-400: The memory allocated to a different one. Around the same time, teleprinters began to be used as terminals so multiple users could access the computer simultaneously. The operating system MULTICS was intended to allow hundreds of users to access a large computer. Despite its limited adoption, it can be considered the precursor to cloud computing . The UNIX operating system originated as
12282-495: The menu in MSN Quick Launch could be dynamically updated to guide members to updated MSN content and services. With the release of MSN 2.6 in 1998, Microsoft renamed the service 'MSN Internet Access', and the MSN Program Viewer was abandoned entirely in favor of the more familiar Internet Explorer. Another new version of the service, MSN Internet Access 5.0, was released along with Internet Explorer 5.0 in 1999. MSN 5.0
12420-408: The need to use it. A general protection fault would be produced, indicating a segmentation violation had occurred; however, the system would often crash anyway. The use of virtual memory addressing (such as paging or segmentation) means that the kernel can choose what memory each program may use at any given time, allowing the operating system to use the same memory locations for multiple tasks. If
12558-500: The object-based file system, which would later evolve into WinFS . Simultaneously with Windows 3.1's release, IBM started shipping OS/2 2.0 . Microsoft realized they required an updated version of Windows that could support 32-bit applications and preemptive multitasking, but could still run on low-end hardware (Windows NT did not). Initially, the "Chicago" team did not know how the product would be packaged. Initial thoughts were there might be two products, MS-DOS 7, which would just be
12696-408: The open-source Android operating system (introduced 2008), with a Linux kernel and a C library ( Bionic ) partially based on BSD code, became most popular. The components of an operating system are designed to ensure that various parts of a computer function cohesively. With the de facto obsoletion of DOS , all user software must interact with the operating system to access hardware. The kernel
12834-420: The operating system acts as an intermediary between programs and the computer hardware, although the application code is usually executed directly by the hardware and frequently makes system calls to an OS function or is interrupted by it. Operating systems are found on many devices that contain a computer – from cellular phones and video game consoles to web servers and supercomputers . In
12972-421: The piping. Signals may be classified into 7 categories. The categories are: Input/output (I/O) devices are slower than the CPU. Therefore, it would slow down the computer if the CPU had to wait for each I/O to finish. Instead, a computer may implement interrupts for I/O completion, avoiding the need for polling or busy waiting. Some computers require an interrupt for each character or word, costing
13110-415: The programmer or the user with the perception that there is a much larger amount of RAM in the computer than is really there. MSN Dial-up MSN Dial-up is an Internet service provider operated by Microsoft in the United States and formerly also in several other countries. Originally named The Microsoft Network , it debuted as a proprietary online service on August 24, 1995, to coincide with
13248-580: The release of Windows 95 . In 1996 and 1997, a revised web-based version of the ISP was an early experiment at interactive multimedia content on the Internet . Microsoft renamed the service MSN Internet Access in 1998, focusing its main ' MSN ' brand on its web portal of the same name, MSN .com. Today, the company still provides dial-up Internet access under the name 'MSN Dial-up' for those who cannot access high-speed broadband . For several years, MSN
13386-543: The release of MSN 2.0 in 1996, Microsoft renamed its original proprietary online service 'MSN Classic'. Microsoft eventually shut down any remaining access to the MSN Classic service in 1998. In 1996, in response to the increasing relevancy and rapid growth of the World Wide Web , Microsoft created a new version of MSN, called 'MSN 2.0', which combined access to the Internet with web-based multimedia content in
13524-418: The same operating system— OS/360 —which consisted of millions of lines of assembly language that had thousands of bugs . The OS/360 also was the first popular operating system to support multiprogramming , such that the CPU could be put to use on one job while another was waiting on input/output (I/O). Holding multiple jobs in memory necessitated memory partitioning and safeguards against one job accessing
13662-480: The segments were allocated as fixed, Windows could not move them, which would prevent any more programs from launching. Microsoft partially removed support for File Control Blocks (an API hold-over of DOS 1.x and CP/M ) in Windows 95 OSR2 ( OEM Service Release 2). FCB functions can read FAT32 volumes, but not write to them. Windows 95 introduced a redesigned shell based around a desktop metaphor ; File shortcuts (also known as shell links) were introduced and
13800-619: The server and supercomputing sectors. Other specialized classes of operating systems (special-purpose operating systems), such as embedded and real-time systems, exist for many applications. Security-focused operating systems also exist. Some operating systems have low system requirements (e.g. light-weight Linux distribution ). Others may have higher system requirements. Some operating systems require installation or may come pre-installed with purchased computers ( OEM -installation), whereas others may run directly from media (i.e. live CD ) or flash memory (i.e. USB stick). An operating system
13938-590: The service of call centers around the world. Among the countries are the Philippines (technical and customer service), El Salvador (technical and customer support for Spanish -speaking customers), and India (customer service). In 2007, Microsoft set up a research and development center for MSN China , based in Shanghai 's Zizhu Science Park, which hosts technical support for MSN services. For customers with high-speed broadband Internet access , MSN Premium
14076-603: The sign-up was done through an 800- (toll-free) phone number which assigned to the user PC an internal IP address of SITA -NET ( Société internationale de télécommunication aéronautique ), in the IP range 57.0.0.0/8, giving the user access to all of the SITA network equipment (so, not only the SITA-managed server involved in the MSN account registration process). MSN has many offices worldwide for national customer support. It utilizes
14214-400: The signal number (in mnemonic format) to be sent. (The abrasive name of kill was chosen because early implementations only terminated the process.) In Unix-like operating systems, signals inform processes of the occurrence of asynchronous events. To communicate asynchronously, interrupts are required. One reason a process needs to asynchronously communicate to another process solves
14352-400: The size of the machine needed. The different CPUs often need to send and receive messages to each other; to ensure good performance, the operating systems for these machines need to minimize this copying of packets . Newer systems are often multiqueue —separating groups of users into separate queues —to reduce the need for packet copying and support more concurrent users. Another technique
14490-411: The software began requiring a user to have a Microsoft account , though depending on the version, it may or may not require an active subscription to other MSN services. The interface also includes many Flash animations. Version 9.5 added compatibility with Windows Vista . Version 9.6 was released in June 2008 and included revisions necessary for a newer mailbox synchronization technology and to replace
14628-542: The software in 2002 in favor of a version only available with MSN dial-up and premium subscriptions. Versions of MSN Explorer later than 7.5 require a paid subscription, but it is possible to use another Internet service provider while accessing content provided through the MSN Explorer software. The last free version of the MSN software also remained available for download for some time. MSN versions 8 and 9 were released in 2002 and 2004 respectively. As of MSN version 9,
14766-448: The standard version of Hotmail in 2008, but with additional storage capacity compared to free Hotmail users. Microsoft phased out Hotmail and replaced it with Outlook.com in 2013, but MSN subscribers still receive @msn.com email addresses to use with the service ad-free. Former members can continue to use those addresses with Outlook.com after ending their subscriptions. An early pre-release version of MSN Explorer, labeled version 1.1,
14904-487: The time before the release of Windows 3.1 . At this time, Windows for Workgroups 3.11 and Windows NT 3.1 were still in development. At this point, Microsoft's strategy was to have a next generation, high-end OS based on Windows NT, namely, Cairo , and a low-end, consumer-focused one as an evolution of Windows 3.1. The latter strategy was to develop a 32-bit underlying kernel and filesystem with 32-bit protected mode device drivers in Windows for Workgroups 3.11, to be used as
15042-494: The transition to MSN 2.0 would break up communities that were established via the MSN Classic message boards and chat rooms. Their concerns were confirmed when Microsoft announced plans to close the entire MSN Classic service. As a result of all these issues, a website called 'The Official msNOT Hate Site' originated as a negative response to the new MSN 2.0 software. The website claimed Microsoft patently ignored feedback from concerned members and censored anyone who spoke out against
15180-401: The transition to MSN Explorer, email for MSN members was integrated into Microsoft's Hotmail architecture and could be accessed from the web the same way as any other Hotmail account. MSN Explorer provided a user interface for navigating one's @msn.com email inbox and folders, also known as 'MSN Mail', until the migration of Hotmail to the Windows Live brand. MSN subscribers were upgraded to
15318-429: The underlying OS, an evolution of the Windows for Workgroups 3.11 kernel, with a character mode OS on top, and a fully integrated graphical Windows OS. But soon into the project, the idea of MS-DOS 7 was abandoned and the decision was made to develop only an integrated graphical OS Windows "Chicago." Before Windows 95's official release, users in the United States and United Kingdom had an opportunity to participate in
15456-447: The upgrade; it further charged the company's handling of the transition to MSN 2.0 was "insensitive and ethically questionable." Microsoft denied it attempted to silence those who expressed concern about the upgrade. The website also mocked the music loop that played during the MSN 2.0 installation process because it repeated the phrase "too stupid to stop." Ultimately, the ambitious use of web-based and interactive multimedia content on
15594-402: The visual style of Windows XP and utilized relatively responsive animations that would not become commonplace in web browsers until HTML5 came along several years later. Microsoft began referring to the MSN Explorer software as simply 'MSN' beginning with version 7, an update that was rolled out shortly after the initial release of Windows XP. Microsoft halted development of the free edition of
15732-528: The world, named MSN Premium . The concept for MSN was created by the Advanced Technology Group at Microsoft, headed by Nathan Myhrvold . MSN was originally conceived as a subscription-based dial-up online service and proprietary content provider like America Online or CompuServe . Then officially known as 'The Microsoft Network', version 1.0 of the service launched along with Windows 95 on August 24, 1995. The Microsoft Network
15870-580: The world. In Canada , MSN partnered with Bell Sympatico (the ISP division of Bell Canada ) creating 'Sympatico / MSN'. In Australia , Microsoft originally partnered with Telstra in 1995 with MSN branded locally as 'OnAustralia'; when Microsoft withdrew from the joint venture the following year, Telstra went on to assume 100% ownership and rebrand the service as BigPond . In Mexico , MSN partnered with Telmex Prodigy creating 'Prodigy / MSN'. An affiliation with Xtra , Telecom New Zealand 's Internet provider, known as XtraMSN ended in 2006. In Italy
16008-473: The world. Middleware , an additional software layer between the operating system and applications, is often used to improve consistency. Although it functions similarly to an operating system, it is not a true operating system. Embedded operating systems are designed to be used in embedded computer systems , whether they are internet of things objects or not connected to a network. Embedded systems include many household appliances. The distinguishing factor
16146-560: Was a dial-up client interface to Microsoft's pay-for-access online services for Mac users. The software was, in some respects, comparable to the AOL dial-up client given its channel-based interface, built-in chat and instant messaging capabilities, parental controls, and ability to accommodate multiple screen names. It used the Tasman layout engine made for the Mac edition of Internet Explorer 5 . It
16284-508: Was a separate product. The Plus! pack did not reach as many retail consumers as the operating system itself (it was mainly advertised for its non-Internet-related add-ons such as themes and better disk compression) but was usually included in pre-installed ( OEM ) sales, and at the time of Windows 95's release, the web was being browsed mainly with a variety of early web browsers such as NCSA Mosaic and Netscape Navigator (promoted by products such as IBox ). Windows 95 OEM Service Release 1
16422-571: Was based around email , chat rooms (which were branded MSN Chat and moved to the standard IRC protocol), and newsgroups (which were moved to Usenet from a proprietary architecture), while a 'Find' section was dedicated to searching MSN content and the rest of the Internet; it also provided a calendar of upcoming events and new shows on MSN. The new content made extensive use of multimedia and interactive features, including VBScript and early implementations of Macromedia Shockwave Flash (originally called 'FutureSplash') for animations. While
16560-480: Was debate in the media as to whether MSN would be an 'Internet killer', and some companies hedged their bets for the first year, creating content both on MSN and the World Wide Web . However, MSN launched too late to be a real threat to the web. Following Bill Gates ' internal 'Internet Tidal Wave memo', which refocused Microsoft to be Internet-centric, MSN began to move its content to the web and promote itself more actively as an Internet service provider . Following
16698-556: Was discontinued in March 2005. After the discontinuation of MSN for Mac OS X, Microsoft continued offering its Microsoft Messenger for Mac software, an instant messaging -only client that required only a free Microsoft account for use. As mentioned previously, Skype replaced Messenger in 2013. Microsoft has extended its MSN dial-up Internet access service beyond the United States since 1995, partnering with various telecommunications companies to provide service in numerous areas around
16836-407: Was essentially an animated, stylized and streamlined interface on top of an Internet Explorer 3 .0 web browser. When members signed in, they would be presented with several different 'Channels', which were categories for the various types of content available on MSN. These channels included new services that launched in 1996 such as msnbc.com , a news website now known as NBCNews.com that began as
16974-518: Was estimated at $ 1 billion and spanned the entire industry. The Windows 95 release included a commercial featuring The Rolling Stones ' 1981 single " Start Me Up " (a reference to the Start button). It was widely reported that Microsoft paid the Rolling Stones between US$ 8 and US$ 14 million for the use of the song in the Windows 95 advertising campaign. However, Microsoft said that this was just
17112-569: Was hung down the side of the CN Tower in Toronto . The release included a number of "Fun Stuff" items on the CD, including music videos of Edie Brickell 's "Good Times" and Weezer 's " Buddy Holly ," a trailer for the 1995 film Rob Roy and the computer game Hover! Sales were strong, with one million copies shipped worldwide in just four days. According to International Data Corporation , by
17250-401: Was included with Windows 95 installations and promoted through Windows and other Microsoft software released at the time. Product support and discussion was offered through the MSN service, as well as information such as news and weather, basic email capabilities, chat rooms , and message boards similar to newsgroups . It also offered access to the Internet via Internet Explorer . There
17388-450: Was introduced as an add-on for Windows 95. Official system requirements were an Intel 386 DX CPU of any speed, 4 MB of system RAM and 50–55 MB of hard disk space depending on features selected. These minimal claims were made in order to maximize the available market of Windows 3.1 migrations. This configuration would rely heavily on virtual memory and was only optimal for productive use on single-tasking dedicated workstations. It
17526-472: Was largely identical to MSN 2.6, aside from offering the newer version of the browser. Also in 1998, Microsoft relaunched its Microsoft Internet Start web portal as MSN .com and began to focus on offering services under the 'MSN' brand name to users of other Internet service providers. Building on the success of MSN's web-based email service, Hotmail (which was acquired by Microsoft in December 1997),
17664-455: Was originally included with a development build of Windows XP . The final release, MSN Explorer version 6.0 (officially numbered to follow the last release of the older MSN 5.0 software), was built into Windows XP with its release in October 2001. Anyone who used Windows XP could choose to use MSN Explorer regardless of their MSN membership status. The user interface for MSN Explorer matched
17802-516: Was originally presented through a Windows desktop icon and sign-in screen that, upon dial-up connection and member authentication, launched an artificial folder-like graphical user interface integrated into the Windows Explorer file management program, with a home page named 'MSN Central'. Categories on MSN appeared like folders in the file system. The interface was designed by Clement Mok and employed high color graphics. MSN
17940-404: Was possible to run Windows 95 on a 386 SX, but this led to even less acceptable performance due to its 16-bit external data bus. To achieve optimal performance, Microsoft recommended an i486 or compatible CPU with at least 8 MB of RAM. Windows 95 may fail to boot on computers with a processor faster than 2.1 GHz and more than approximately 480 MB of memory. In such a case, reducing
18078-516: Was presented in a TV-like format, dubbed MSN shows, as part of the 'On Stage' section. The many shows and sites included an interactive online nightly game show called 'Netwits', a snarky website addressing women's issues called 'UnderWire', and a regular celebrity interview and web-surfing session called 'One Click Away'. These new destinations supplemented other Microsoft web-based services such as CarPoint and Expedia , which were branded within MSN as 'Essentials'. An additional 'Communicate' section
18216-595: Was released in April 2014 and offers compatibility with Windows 8 and Internet Explorer 11 , adds tabbed browsing , and brings back a 'remember me' feature. The software still included an instant messaging client based on Microsoft's Messenger service, even though it had been phased out in favor of Skype since 2013. Subsequent releases of MSN 11 included updated email functionality to maintain compatibility with Outlook.com in version 11.5, and updated logos to match current MSN branding in version 11.6. MSN for Mac OS X
18354-521: Was replaced by Windows Explorer and the Explorer-based Control Panel and several other special folders were added such as My Computer, Dial-Up Networking, Recycle Bin, Network Neighborhood, My Documents, Recent documents, Fonts, Printers, and My Briefcase among others. AutoRun was introduced for CD drives. The user interface looked dramatically different from prior versions of Windows, but its design language did not have
18492-564: Was sold as a shrink-wrapped product; later editions were provided only to computer OEMs for installation on new PCs. For this reason, these editions are known as OEM Service Releases ( OSR ). Together with the introduction of Windows 95, Microsoft released the Microsoft Plus! for Windows 95 pack, which contained several optional components for high-end multimedia PCs, including Internet Explorer, DriveSpace and additional themes. Operating system An operating system ( OS )
18630-556: Was still offered through the MSN Program Viewer, but the service primarily directed members to traditional text-based websites that anyone on the Internet could access, instead of interactive shows. Beginning with MSN 2.5, email service for MSN members was moved from a proprietary Microsoft Exchange environment that powered email for both MSN Classic and MSN 2.0, to standard POP3 and SMTP protocols that could be accessed via any Internet email program, including Microsoft's own Internet Mail and News , which became Outlook Express with
18768-406: Was the first popular computer to use a graphical user interface (GUI). The GUI proved much more user friendly than the text-only command-line interface earlier operating systems had used. Following the success of Macintosh, MS-DOS was updated with a GUI overlay called Windows . Windows later was rewritten as a stand-alone operating system, borrowing so many features from another ( VAX VMS ) that
18906-462: Was the first release of Windows to include Internet Explorer (version 2.0 ) with the OS. While there was no uninstaller, it could be deleted easily if desired. OEM Service Release 2 included Internet Explorer 3 . The installation of Internet Explorer 4 on Windows 95 (or the OSR2.5 version preinstalled on a computer) gave Windows 95 Active Desktop and browser integration into Windows Explorer, known as
19044-470: Was the second largest dial-up ISP in the United States behind longtime leader AOL , but very few people in the U.S. still rely on dial-up. Along with dial-up service, MSN provides its subscribers with an @msn.com email account to use with Outlook.com and security software such as firewall and anti-virus programs. Alongside MSN Dial-up, Microsoft also offer these as a standalone subscription service for users with broadband Internet access around
#99900