Build list legend
|Version of Microsoft Windows|
|OS family||Windows NT|
|Architecture||x86 (PC/AT, PC-98), DEC Alpha, MIPS, PowerPC|
|Latest build||3.51.1057.6 (Service Pack 5)|
|Release date||1994-09-21 (3.5)|
2002-09-30 (Server 3.51)
|Windows NT 3.1|
|Windows NT 4.0|
Windows NT 3.5x is a family of NT-based operating systems released by Microsoft. These versions of Windows are the last of the NT series with the Windows 3.1-style user interface, as Windows NT 4.0 would introduce the Windows 95-style shell. These versions succeeded Windows NT 3.1, released in 1993.
Notably, an early version of the Windows 95-style shell is available for Windows NT 3.51 via the NewShell update. NewShell replaces Program Manager and adds a new desktop, taskbar, and user interface graphics. Windows NT 3.5x builds are known to install itself into the
WINNT35 folder instead of
WINNT. This change was reverted in Windows NT 4.0.
On 31 December 2001, Microsoft declared Windows NT 3.5x obsolete and stopped providing support and updates for the system. However, Windows NT Server 3.51 continued to be distributed until 30 September 2002.
On 15 May 2020, the source code for Windows NT 3.5 build 782 was leaked.
It is notably the last version of Windows NT to be distributed under 3.5-inch floppy disks.
According to Microsoft, the x86 versions of Windows NT 3.5 and Windows NT 3.51 require an 80386 processor, at least 16 MB of RAM, 95 MB of hard drive space, and a VGA or better display.
Windows NT 3.5 does not support processor generations higher than the original Pentium due to a faulty processor check during setup. Windows NT will state the processor as incompatible and abort setup without additional patching of setup files. Windows NT 3.51 fixes the aforementioned issue.
Windows NT 3.5 (codenamed Daytona) was released on 21 September 1994. It is the first version to feature the edition names of 'Workstation' (previously called simply "Windows NT") and 'Server' (previously called "Advanced Server"). It cannot be installed on a computer with a processor newer than the original Pentium without modifying setup files.
A less-common PowerPC version targeting the PowerPC Reference Platform was also released, but was largely downplayed in favor of promoting compatibility with Windows NT 3.51.
Windows NT 3.51 is the first release of Windows NT to introduce PCMCIA support, NTFS file compression, replaceable GINA (exclusive to the Server SKU), 3D acceleration in OpenGL, Windows 95-styled common controls, as well as new versions of Sound Recorder, Media Player and Windows Help applications. It was released on 30 May 1995, eight months after the release of Windows NT 3.5, and three months before the release of Windows 95. It is the last version of Windows NT compatible with the 386 processor and the last Windows version to contain the Write word processor.