It depends on where you are going to use operating system. For gaming it's better to use Windows xp or vista depending how powerful your PC is. For servers it's better to use Linux based systems like Fedora, Ubuntu (it's free) and so on.
Windows XP was the most popular operating system.
Windows 8 is the most current windows client operating system.
Microsoft Windows.
Windows is the most best operating system
windows xp
windows of course
windows of course
Microsoft Windows
If you are referring to the operating system then a Mac's default operating system is called Mac OS X. A Mac can be downgraded to run most versions of the Windows operating system from XP to 7.
Do you mean Windows? It's the most popular and compatible operating system available from Microsoft.
No, you can create multiple accounts on most of the OS's
Windows is the most widely-used desktop operating system made by Microsoft.