Originally Posted by xHassassin
Reinstall works everytime.
its pointless to reinstall a game that comes in packs (gcf's for valve games) as the contents of the packs are locked.
Merely deleting settings as DMX has suggested, as well as custom models and misc media is the most efficient way of starting anew (ie. delete your ..\steamapps\<your profile>\team fortress 2\tf)