Okay, here's the problem. Last night my little brother wanted to install the new Splinter Cell game to play on my rig. I don't have much memory left, so I told him he could uninstall my copy of Unleashed 2 since I wouldn't need it again till the DLC came out. Trouble is, he thought the best way to do this would be to go into program files and delete the folder manually. So now I can't uninstall it properly and when I stick in the disk it acts like the game is still installed... except of course I can't play. I'll be wanting to play again pretty soon and I'm at a total loss. Any help would be greatly appreciated.

You could try Revo Uninstaller, if it finds a TFU2 install it can easily uninstall it.