This is the notice I get whenever I try to play music or video with WMP:
Windows Media Player cannot find the file. If you are trying to play, burn, or sync an item that is in your library, the item might point to a file that has been moved, renamed, or deleted.
This is the first time I've used WMP on this computer - it's new. I haven't moved or customized anything and it can't even find the music or video files that came loaded on the computer out of the box.