systeminfo | findstr OS
winver

Operating system               Version number
Windows 10.0                   10.0 (Build xxxxx)
Windows 8.1                    6.3*
Windows Server 2012   R2       6.3*
Windows 8                      6.2
Windows Server 2012            6.2
Windows 7                      6.1
Windows Server 2008   R2       6.1
Windows Server 2008            6.0
Windows Vista                  6.0
Windows Server 2003   R2       5.2
Windows Server 2003            5.2
Windows XP 64-Bit Edition      5.2
Windows XP                     5.1
Windows 2000                   5.0