Windows NT 4.0
A version of the Windows NT operating system
Windows logo 1995
300px-Windows NT 4
Windows NT 4.0's Active Desktop Update

displaying its desktop, taskbar, and quick launch bar.

Developer Microsoft
Source model Closed source
Released to


July 31, 1996; 22 years ago
General availablity August 24, 1996; 22 years ago
Latest release Service Pack 6a
(4.0.1381) /
October 21, 2002; 16 years ago
Platforms IA-32, Alpha, MIPS, PowerPC
Kernel type Hybrid
License Commercial proprietary software
Preceded by Windows NT 3.51 (1995)
Succeeded by Windows 2000 (1999)
Support status
Embedded Mainstream support ended on June 30, 2003

Extended support ended on July 11, 2006

Server Mainstream support ended on December 31, 2002

Extended support ended on December 31, 2004

Workstation Mainstream support ended on June 30, 2002

Extended support ended on June 30, 2004

Windows NT 4.0 is a preemptively multitasked, graphical operating system, designed to work with either uniprocessor or symmetric multi-processor computers. It was part of Microsoft's Windows NT line of operating systems and was released to manufacturing on July 31, 1996 and was released for retail sale on August 24, 1996. It is a 32-bit Windows system available in both workstation and server editions with a graphical environment similar to that of Windows 95.


  • The last version of Windows Media Player to run on Windows NT 4.0 is Windows Media Player 7.
  • The last version of Internet Explorer to run on Windows NT 4.0 is Internet Explorer 6 SP1.
  • The last version of Microsoft Office to run on Windows NT 4.0 is Office XP.

Service packsEdit

Service pack Release date
Service Pack 1 (SP1) October 16, 1996
Service Pack 2 (SP2) December 14, 1996
Service Pack 3 (SP3) May 15, 1997
Service Pack 4 (SP4) June 25, 1998
Service Pack 5 (SP5) October 31, 1999
Service Pack 6 (SP6) December 28, 2000
Service Pack 6a (SP6a) July 26, 2001

Microsoft released Windows NT 4.0 service packs primarily to fix bugs. Windows NT 4.0, during its lifecycle, had several service packs, as well as numerous service rollup packages and option packs. The last full service pack was Service Pack 6a (SP6a).

A SP7 was planned at one stage in early 2001, but this became the Post SP6a Security Rollup and not a full service pack, released on July 26, 2001, 16 months after Windows 2000 and nearly three months prior to Windows XP.