Operating System Beta, etc. Wiki

Windows 95 is a consumer version of Windows released by Microsoft. It was designed to be the successor of Windows 3.1, and would be replaced by Windows 98. Microsoft ended support for Windows 95 on 2001-12-31.

It was improved upon 16-bit Windows by introducing a 32-bit kernel and eliminating the need for an existing installation of MS-DOS, making it a standalone operating system (running alongside MS-DOS). Microsoft concentrated on improving the usability of Windows with technologies such as Plug-and-Play, long file names (VFAT), the Start Menu, an updated Desktop, Internet Explorer and Mail, built-in networking, and virtual device drivers. Many of the paradigms introduced with Windows 95 still remain in use today.

User Interface

Windows 95 introduced an updated shell and desktop, including Windows Explorer (which replaced File Manager) and the Start Menu (which replaced Program Manager). This basic layout would be used until Windows 8, and later reintroduced in Windows 10.

The user interface is divided up into the Start Menu, which is used to launch applications, and the taskbar, which displays running programs and controls their windows.


Windows 95 was a revolutionary update for Windows, and also the first concerted effort by Microsoft to listen to consumers. Although it was still built upon the solid, if out-dated, foundations of MS-DOS, the average user never saw the MS-DOS prompt unless they actually wanted to. Windows NT was too intensive for most computers of the time, and it was not until after the release of Windows 95 that Win32 applications were widely used and supported.


The development of Windows 95 started in 1992 shortly after the release of Windows 3.1. Pre-release Windows for Workgroups 3.1 builds were forked into the Cougar project, a 32-bit protected mode kernel to be used in the next Windows release (at the time often called Windows 4.0 or Windows 93). Cougar was later merged with Jaguar (known as MS-DOS 7.0, also slated for a separate release) into Chicago, which became Windows 95. The first two builds known to exist are the Usability Testing Builds from January 1993, seen in a Microsoft video.[1] The first leaked build is 58s, knows as PDK/M4 from August 1993, followed by 73g (PDK2/M5 from November 1993), 81 (January 1994) and finally beta 1 builds 99, 116 and 122 (May 1994), beta 2 (October 1994) and RC (throughout 1995).



Pre-Milestone 4

Milestone 4 & Milestone 5


(official M5)

(internal M5)

Buildlist-BlueDoubtful.png 4.00.83
Buildlist-BlueDoubtful.png 4.00.84
Buildlist-BlueDoubtful.png 4.00.89
Buildlist-BlueDoubtful.png April 1994 release

(internal M5)

Evidence for a build between 81 and 99 exists in the InfoWorld magazine of 1994-05-23 and was also scene leaked.

Beta 1/Milestone 6

(official Beta 1/M6)

Buildlist-BlueDoubtful.png 4.00.176

Beta 2/Milestone 7

Buildlist-BlueDoubtful.png 4.00.265

Beta 3/Milestone 8

Release Candidate 1

(official RC1/M9)


Release to Manufacturing (RTM)

Buildlist-Green.png 4.00.950
Buildlist-Green.png 4.00.951

(r-7 RTM, mid-1997)

OEM Service Release 1

Buildlist-Green.png 4.00.950a

OEM Service Release 2


Buildlist-Green.png 4.00.1034
Buildlist-BlueDoubtful.png 4.00.1048
Buildlist-BlueDoubtful.png 4.00.1054

(Y2K hotfix, code base for Windows 98)

Buildlist-Green.png 4.00.1094


OEM Service Release 2.1


Buildlist-Green.png 4.03.1107


Buildlist-Green.png 4.03.1212 (950b)
Buildlist-Green.png 4.03.1214 (950b)

OEM Service Release 2.5

Buildlist-Green.png 4.03.1216 (950c)