Windows NT 3.1

Windows NT 3.1 is the first version of Windows NT. It was targeted for the Intel i860 CPU, but was ported to the MIPS platform in 1989 and to the Intel 386 in 1990. Later on it was also released for the DEC Alpha.

Its codename was NT OS/2 due to the fact that Windows NT was initially going to be OS/2 3.0. However, even before OS/2 2.0 was completed, IBM and Microsoft ended their partnership and the latter developed Windows NT on their own and the new OS was very reminiscent of OS/2. For example, the NTFS file system it introduced is heavily based upon IBM's HPFS used in OS/2, both even use the same disk partition ID. It was succeeded with the Windows NT 3.5x family and was also the first version by Microsoft to no longer be supported, as it was unsupported 1 year before most other older Microsoft products went out of support.