Windows Media Player 11 (Vista32bit) won't play anything, but all other features (library, etc.) work fine?

I think I have a pretty unique problem. Currently running 32-bit Vista on a Dell Latitude notebook. Every instance I try to play a song file or video through WMP11, it doesn't play. The music timer will sit at 0:00 for about five seconds, change to 0:01, and then never move from there. All the other features, such as browsing through the library, work fine. WMP doesn't exactly crash either. Help!