- Windows NT 3.1 is the first major release of the Windows NT operating system developed by Microsoft, released on July 27, 1993.
- Windows NT 3.5 (Wikipedia)
Windows NT 3.5 is a major release of the Windows NT operating system developed by Microsoft and oriented towards businesses. It was released on September 21, 1994, as the successor to Windows NT 3.1 and the predecessor to Windows NT 3.51.
- Windows 3.1 (Wikipedia)
Windows 3.1 is a major release of Microsoft Windows. It was released to manufacturing on April 6, 1992, as a successor to Windows 3.0.
- Microsoft Windows (Wikipedia)
Microsoft Windows is a product line of proprietary graphical operating systems developed and marketed by Microsoft. It is grouped into families and sub-families that cater to particular sectors of the computing industry – Windows (unqualified) for a consumer or corporate workstation, Windows Server for a server and Windows IoT for an embedded system. Defunct families include Windows 9x, Windows Mobile, Windows Phone, and Windows Embedded Compact.