If VLC refuses to play it, it usually means the file is no good...
But just to be sure try downloading the codecs for WMP...
This thread has a list of Codecs you can use..
http://www.gnutellaforums.com/showth...threadid=40665
You didn't say what OS you are using, if you are using xp this pac is good...
http://www.xpcodecpack.com/