Sound Card

ok first of all...i've tried fixing it, but how can you fix it when you don't know whats wrong? sound plays on my computer for only 1 song wether its through yahoo or windows media player. after that one song an error report type thing pops up and says--"Windows Media Player has encountered a problem and needs to close. We are sorry for the inconvenience." that was for windows media player. it does it when u stop a song and go to a different one, let the whole song play, or stop it. the only thing it doesn't affect is aol...i can listen to music all i want on it and the error won't pop up on it. I can copy the error report if you need, but please give me some pointers. thanx