Operating System Beta, etc. Wiki

Windows NT 4.0 User Interface

Windows NT 4.0 (codenamed Cairo & Shell Update Release) is the successor to Windows NT 3.51 and the first version of Windows NT to feature the Windows Explorer interface introduced in Windows 95. It is the last version of Windows NT to include NT in its product name.

It should not be confused with Windows codename Cairo, of which two builds are known and leaked: 854, and an alternate release of 1175.

The Windows Desktop Update further enhances the shell by incorporating features from Windows 98.


There are several editions of Windows NT 4:

  • Workstation
  • Server
  • Server Enterprise Edition
  • Terminal Server (Codename: Hydra)

Service Packs

There were 6 service packs released for Windows NT 4. There was a 7th Service Pack Planned, but it was canceled and Update Rollup 6a was released instead.


Pre-Beta 1

Buildlist-BlueDoubtful.png 4.0.1096.1
Buildlist-BlueDoubtful.png 4.0.1116.1
Buildlist-BlueDoubtful.png 4.0.1124.1
Buildlist-BlueDoubtful.png 4.0.1128.1
Buildlist-BlueDoubtful.png 4.0.1150.1

Beta 1

Buildlist-Green.png 4.0.1227.1
Buildlist-BlueDoubtful.png 4.0.1249.1
Buildlist-BlueDoubtful.png 4.0.1261.1
Buildlist-Green.png 4.0.1264.1

Beta 2

Buildlist-Green.png 4.0.1314.1

Pre-Release Candidate 1

Buildlist-BlueDoubtful.png 4.0.1326.1
Buildlist-Green.png 4.0.1327.1
Buildlist-BlueDoubtful.png 4.0.1332.1

Release Candidate 1

Release Candidate 2

Buildlist-Green.png 4.0.1359.1



Service Pack 1

Buildlist-Green.png 4.0.1381.2

Service Pack 2

Buildlist-Green.png 4.0.1381.3

Service Pack 3

Buildlist-Green.png 4.0.1381.4

Service Pack 4

Buildlist-Green.png 4.0.1381.133

Service Pack 6 without a

Buildlist-Green.png 4.0.1381.335

Service Pack 6a

Post-Service Pack 6a Security Rollup

Terminal Server Edition

The Terminal Server Edition was Launched in 1997, Since until Final Release in September 1998, It included Service Pack 3.

It also can be Upgraded Citrix WinFrame 1.8 (NT 3.51 Terminal Server) to NT 4.0 TSE.

Beta 1

Beta 2

Terminal Server Edition RTM

Service Pack 4

Buildlist-Green.png 4.0.1381.1024

Service Pack 5

Buildlist-Green.png 4.0.1381.1280

Service Pack 6

Buildlist-Green.png 4.0.1381.1536

Source Leak

For detailed information, see the main article: Windows Source Code

In 2004, a large portion (approximately 80-95%) of the Windows NT 4.0 (With Service Pack 3) source code was leaked. Further investigations by Microsoft found that the source was leaked from Mainsoft, a software porting company (which ported Internet Explorer to Unix before such edition was dropped).

In 2010, The source was successfully compiled by Kenneth, a BetaArchive and Windows Projects Community member, producing about 318MB of binaries.