If you use Windows Media Player as your DJ during a party, it has a nice locking feature that you can use during parties. Just open Windows Media Player and put it into full-screen mode. Once you do that, there will be a small lock icon (with the hasp unlocked) in the lower right hand corner of the screen. If you click on this lock, it'll open up a small input box and ask you to enter a 4 digit PIN to lock the screen. Once you lock the screen, you can still use the interface for Windows Media Player, you just can't get out of Windows Media Player. This is a great option to use if your computer is on during a party and you don't want people snooping around on your computer. It's not full-on security, all you have to do to circumvent the lock is turn off the computer (which is good to know in case you don't lock Windows Media Player and a friend locks your screen as a joke), but it'll dissuade most snoopers... and if they turn off your computer during the middle of the party, the music will turn off and it'll be pretty obvious what's goin on.