Windows NT 3.x NT 3.1 Pre-Release

Windows NT 3.1 was the first of the Windows NT series. Sporting the same face as its consumer counterpart Windows 3.1, it was completely different under the hood. A true 32-bit native operating system, Windows NT descended from the work Microsoft did while collaborating with IBM on OS/2 after the great split, and bringing in former DEC employees like Dave Cutler, bringing a VMS influence into the system. It was followed up by Windows NT 4.0.


Release notes

These builds are early pre-releases, that lead up to the final NT 3.1. They are ocasionally referred to as "NT OS/2", as the core technology was developed by Microsoft for use in future IBM OS/2 products. However, after the IBM-MS split, it became "Windows", and is branded as such.

The very first builds are visibly little more than the Win16 API and Windows 3.x GUI ported to a 32-bit system.

Product type
Release date
Minimum CPU
User interface
Download count
114 (1 for release)


Download name Version Language Architecture File size Downloads
Microsoft Windows NT 3.1 (10-16-1991) October 1991(ISO) 3.1 (10-16-1991) Prerelease English 13.15MB 0
Microsoft Windows NT 3.1 (3.10.196) (9-16-1991) SDK (ISO) 3.10.196 SDK Prerelease English 39.02MB 1
Microsoft Windows NT 3.1 ( (12-20-1991) SDK (ISO) SDK Prerelease English 21.84MB 0
Microsoft Windows NT 3.1 (3.10.297) (6-28-1992) SDK (ISO) 3.10.297 SDK Prerelease English 45.24MB 0
Microsoft Windows NT 3.1 (3.10.328.1) (10-12-1992) SDK (ISO) 3.10.328.1 SDK Prerelease English 48.35MB 0
Microsoft Windows NT 3.1 (3.10.340) (10-12-1992) (3.5-1.44mb) 3.10.340 Prerelease English 15.43MB 0
Microsoft Windows NT 3.1 (3.10.340.1) (10-12-1992) Lan Manager (3.5-1.44mb) 3.10.340.1 Lan Manager Prerelease English 15.55MB 0
Microsoft Windows NT 3.1 (3.10.404) (3-7-1993) (ISO) 3.10.404 Prerelease English 27.76MB 0
Microsoft Windows NT 3.1 (3.10.438) (4-22-1993) (ISO) 3.10.438 Prerelease English 40.09MB 0
Microsoft Windows NT 3.1 (3.10.475) (6-9-1993) (3.5-1.44mb) 3.10.475 Prerelease English 28.13MB 0


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