Windows NT 3.51
| Version of the Windows NT operating system | |
| Developer | Microsoft |
|---|---|
| Source model | Closed source |
| General availability | May 30, 1995 |
| Latest release | Service Pack 5 (3.51.1057.6) / September 19, 1996 |
| Marketing target | Business and Server |
| Platforms | IA-32, Alpha, MIPS, PowerPC |
| Kernel type | Hybrid |
| Userland | Windows API, NTVDM, OS/2 1.x, POSIX.1 |
| License | Commercial proprietary software |
| Preceded by | Windows NT 3.5 (1994) |
| Succeeded by | Windows NT 4.0 (1996) |
| Support status | |
| Server | Mainstream support ended on September 30, 2000 Extended support ended on September 30, 2002 |
| Workstation | Mainstream support ended on December 31, 2000 Extended support ended on December 31, 2001 |
Windows NT 3.51 is the third major release of the Windows NT operating system, developed by Microsoft for the data server and personal workstation markets. It was released on May 30, 1995, eight months following the release of Windows NT 3.5. The most significant enhancement offered in this release was that it provides client/server support for inter-operating with Windows 95, which was released almost three months after NT 3.51. Windows NT 4.0 became its successor a year later. Mainstream support for Windows NT 3.51 Workstation ended on December 31, 2000, and extended support ended on December 31, 2001, while Windows NT 3.51 Server mainstream support ended on September 30, 2000, followed by extended support on September 30, 2002. Both editions were succeeded by Windows NT 4.0 Workstation and Windows NT 4.0 Server, respectively.