Table showing internal version numbers of the various versions of the Microsoft Windows kernel. The names in bold are those used by Microsoft to market the releases.

To reach "Windows 7", Microsoft appear to have grouped previous releases by their internal version number, but considered Windows 7 a major release of Windows, without bumping that internal version number.

MS-DOS based Windows Windows NT and successors
Product (Release) Version Product Version
1 Windows 1.x 1.01 1
1.02
1.03
1.04
2 Windows 2.x 2.03 2
2.1
3 Windows 3.x 3.0 Windows NT 3.x NT 3.1.528 3
3.1 NT 3.5.807
3.11 NT 3.51.1057
4 Windows 95 Retail 4.00.950 Windows NT 4.x NT 4.0.1381 4
OSR 1 4.00.950A
OSR 2/"95B" 4.00.950B / 4.00.1111
OSR 2.5/"95C" 4.00.950C / 4.03.1214
Windows 98 Original 4.1.1998
Second Edition 4.1.2222
Windows Me 4.9.3000
5 Windows 2000 NT 5.0.2195 5
Windows XP NT 5.1.2600
Windows Server 2003 NT 5.2.3790
6 Windows Vista NT 6.0.6000 6
Windows Server 2008
Windows 7 NT 6.1.7600
Windows Server 2008 R2
Windows 8 NT 6.2.9200
Windows Server 2012
Windows 8.1 NT 6.3.9600
Windows Server 2012 R2
10 Windows 10 NT 10.0 10
Windows Server 2016
Windows 11