total no of operating systems exist on earth {part:-5}

Operating systems (573)

V2 OS
Vapour
VERSAdos
Visopsys
Visual Network OS
VM/ESA
VM/VSE
VME
VMS
VRTX/8002
VRTX/OS
VSE
VSOS
VSTa
VTOS
VxWorks
WEGA
Whitix
WildMagnolia
Windows 1.0
Windows 2.0
Windows 3.0
Windows 3.1
Windows 7
Windows 95
Windows 98
Windows 98 SE
Windows 2000
Windows 2003 Server
Windows CE
Windows ME
Windows NT
Windows Server 2008
Windows Vista
Windows XP
WinMac
WIZRD
x-kernel
XAOS
Xenix
Xinu
xMach
XOS
XTS
Yamit
Yaxic
Yoctix
z-VM
z/OS
Z9001-OS
ZealOS
Zeta
Zeus Zilog
zeVenOS
ZMOS
ZotOS
ZRTS 8000