Windows NT 4.0

Microsoft Windows NT 4.0 (codenamed 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.

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

Editions
There are two editions of Windows NT 4.0. It has been found out that the only difference between the two editions (Server and Workstation) lied only in the Registry and the missing Server files.

Workstation
Windows NT 4.0 Workstation was designed for general desktop use.

Server
Windows NT 4.0 Server (Server, Server Enterprise Edition, Terminal Server) were designed to serve web pages to multiple clients using IIS.

Terminal Server
The Terminal Server edition (codenamed Hydra) was released roughly a year after Windows NT 4's RTM. Its technology later merged into the Remote Desktop Protocol by Microsoft.

Service Packs
There were 6 service packs released for Windows NT 4.

Service Pack 7
There was a 7th Service Pack planned, but it was canceled and Security Update Rollup 6a was released instead. In a support document titled "Update on Windows NT 4.0 Service Pack 7", Microsoft stated that:

Pre-Beta 1

 * Windows NT 4.0 Build 1124.1
 * Windows NT 4.0 Build 1130.1
 * Windows NT 4.0 Build 1141.1
 * Windows NT 4.0 Build 1166.1
 * Windows NT 4.0 Build 1175.1
 * Windows NT 4.0 Build 1198.1
 * Windows NT 4.0 Build 1201.1
 * Windows NT 4.0 Build 1209.1
 * Windows NT 4.0 Build 1227.1

Beta 1

 * Windows NT 4.0 Build 1234.1
 * Windows NT 4.0 Build 1264.1
 * Windows NT 4.0 Build 1273.1
 * Windows NT 4.0 Build 1287.1
 * Windows NT 4.0 Build 1293.1

Beta 2

 * Windows NT 4.0 Build 1314.1
 * Windows NT 4.0 Build 1327.1

Release Candidate 1

 * Windows NT 4.0 Build 1345.1 - Release Candidate 1.3
 * Windows NT 4.0 Build 1353.1

Release Candidate 2

 * Windows NT 4.0 Build 1369.1

There was also an unidentified Workstation RC2 build, mentioned in Fate 103 warez CD.

Pre-RTM

 * Windows NT 4.0 Build 1381.1 (pre-release)

RTM

 * Windows NT 4.0 Build 1381.1

Service Pack 1

 * Windows NT 4.0 Build 1381.2

Service Pack 2

 * Windows NT 4.0 Build 1381.3

Service Pack 3

 * Windows NT 4.0 Build 1381.4

Service Pack 4

 * Windows NT 4.0 Build 1381.43
 * Windows NT 4.0 Build 1381.52
 * Windows NT 4.0 Build 1381.133

Service Pack 5

 * Windows NT 4.0 Build 1381.204

Service Pack 6

 * Windows NT 4.0 Build 1381.299 - Service Pack 6 Beta
 * Windows NT 4.0 Build 1381.335

Service Pack 6a

 * Windows NT 4.0 Build 1381.335a

Post-Service Pack 6a Security Rollup

 * Windows NT 4.0 Build 1381.7097

Source code 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 producing about 318MB of binaries.