You're running Windows 2000 or NT; there is no Windows 2000 NT (though Windows 2000 was originally called NT 5.0, and shows 'Built on NT technology' on startup). But assuming you're running Windows 2000...
If you can't get Quicktime or Windows Media Player to work, it's specific to your system, or possibly your sysadmin is being evil; I use both all the time at home and at work (both systems running Windows 2000).