Product Code Database
Windows 95 is a consumer-oriented operating system developed by Microsoft and the first of its Windows 9x family of operating systems, released to manufacturing on July 14, 1995, and generally to retail on August 24, 1995. Windows 95 merged Microsoft's formerly separate MS-DOS and Microsoft Windows products into a single product 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 a mainly cooperatively multitasked 16-bit architecture of its predecessor Windows 3.1 to a 32-bit preemptive multitasking architecture.
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, the notification area, file shortcuts on the desktop, plug and play driver integration, removal of the requirement to have a separate copy of MS-DOS, the ability to full screen application windows, native internet integration, raising the maximum letters a filename can have from eight to 255, the Windows Explorer, and the "Start" button which summons the Start menu. Accompanied by an extensive marketing campaign that generated much prerelease hype, it was a major success and is considered to be one of the biggest and most important products in the personal computing industry. Three years after its introduction, Windows95 was followed by Windows98. Microsoft ended mainstream support for Windows95 on December 31, 2000. Like WindowsNT3.51, which was released shortly before, Windows95 received only one year of extended support, ending on December 31, 2001, the same day as classic versions such as Windows 3.x.
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 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."
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 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 protected memory segments, which can be adjusted to any desired size, and memory areas outside the segment cannot be accessed by a program, that limited harm to other programs and the system when a program crashed. Before this, programs used fixed non-exclusive 64 KB segments. While 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. Unfortunately for compatibility reasons some parts of the 32-bit Windows program memory was non-exclusive and shared among the whole system (most famously the first 1MiB of the address space), this meant that in Windows 95 a crash which incorrectly modified this shared memory could still cause harm to other programs or the system (full memory protection only came to consumer Windows systems with the launch of Windows XP).
The Win32 API is implemented by three modules, each consisting of a 16-bit and a 32-bit component:
When 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 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, the MS-DOS component in Windows 95 responds to a pressed 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 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 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.
With merging Windows together with MS-DOS, Microsoft had effectively Vendor lock-in users who may have been using a different non-Microsoft DOS, like PC DOS and DR DOS, who could previously make use of Windows 3.x without requiring Microsoft's MS-DOS. Caldera demostrated that Windows 95 could in fact run on top of its DR DOS operating system, and argued that Microsoft was being anti-competitive, which would prove useful in a later court case between Caldera and Microsoft. [5]
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, 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 was replaced by Windows Explorer and the Explorer-based Control Panel and several other 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, empathizing more detail; however, its design language did not have a special name like Metro in Windows 8, Windows 8.1, and Windows 10, Platinum in Mac OS 8 and Mac OS 9, Windows Aero in Windows Vista onward, Aqua in macOS, and Material Design in most Google products since 2014. 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 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. The previous "tada" startup sound from Windows 3.1 became the shutdown sound for Windows 95. In 2025, the Microsoft Sound was selected for preservation in the National Recording Registry by the Library of Congress for being "culturally, historically or aesthetically significant".
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 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 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.
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 is often no longer used for managing hard disks. DOS can be used for running old-style device driver 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 a user to fix problems relating to loading native, protected-mode drivers.
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 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 -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 the CD-ROM version might have featured. Microsoft Plus! for Windows 95 was also available on floppy disks.
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 the .NET Framework, versions 2.0 and 3.5 were unofficially Backporting for the operating system in 2024.
Windows 95 OEM Service Release 1 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, 486 or later processor is required) gave Windows 95 Active Desktop and browser integration into Windows Explorer, known as 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 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).
In the UK, the largest computer chain, PC World, received 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 banner 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 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.
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.
The first service pack was made available half a year after the original release and fixed several small bugs.
The second service pack mainly introduced support for new hardware, most notably support for hard drives larger than 2 GB in the form of the FAT32 file system. This release was never made available to end-users directly and was only sold through OEMs (OSR2) with the purchase of a new PC.
A full third service pack was never released, but two smaller revisions to the second were released in the form of a USB Supplement (OSR2.1) and the Windows Desktop Update (OSR2.5). Both were made available as updated disc images shipped by OEMs, and the Windows Desktop Update was also released with the standalone Internet Explorer 4.0 release. OSR2.5 was notable for featuring several changes to the Windows Explorer, integrating it with Internet Explorer 4.0—this version of Internet Explorer looks very similar to the one featured in Windows 98.
Many features have since become key components of the Microsoft Windows series, such as the Start menu and the taskbar, originated in Windows 95. Neil MacDonald, a Gartner analyst, said that Windows 95 "was a quantum leap in difference in technological capability and stability." Ina Fried of CNET said that "by the time Windows 95 was finally ushered off the market in 2001, it had become a fixture on computer desktops around the world."
The basic design of Windows 95, with its combination of a desktop that can be used as a storage location, a pop-out application menu, and a taskbar showing running applications, a clock and a system tray, was strongly influential on future user interfaces for desktop operating systems. The core UI concepts of Windows 95 have persisted up to the present day in both Windows itself as well as on other operating systems like Linux, with the default behaviour of desktop environments like KDE and XFCE replicating it in many aspects.
Even though support for Windows 95 has ended, the software has occasionally remained in use on legacy systems for various purposes. In addition, some video game enthusiasts choose to use Windows 95 for their legacy system to play old DOS games, although some other versions of Windows such as Windows 98 can also be used for this purpose.
In April 2025, The Microsoft Sound was selected to the National Recording Registry by the Library of Congress for being "culturally, historically, and/or aesthetically significant".
Third-party:
Editions
Several Windows 95 editions have been released. Only the original release was sold as a shrink-wrapped product; later editions were provided only to computer for installation on new PCs. For this reason, these editions are known as OEM Service Releases ( OSR).
Reception
As the cover story of its August 1995 issue, PC World featured an extensive review of the system, highlighting new features and shortcomings, with an editorial by the magazine's editor in chief stating that staff consensus about the user interface was "a standing ovation, with more than a few raspberries for the Explorer"
/ref> In its October 1995 Emory Report, Emory University praised the system'
/ref> A November 1996 column in Fortune acknowledged the system's widespread adoption but scrutinized its bugs, hardware requirements, and Microsoft'
/ref>
Legacy
On December 31, 2001, Microsoft ended its support for Windows 95, making it an "obsolete" product per the Microsoft Lifecycle Policy. Internet Archive
See also
Further reading
Microsoft:
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