Huge problem with sound in XP Pro

Ok, i have all my cds backed up to my hard drive, using windows media player
9. i listen to them all the time. at least i did. i copied some of my cds on
my laptop, then transfered them over to my desktop, and when i tried to play
one, it made a horrible skipping noise, non stop. just a contiuous da da da
da da da da da da da da da (super fast) when i closed wmp9, the sound didnt
stop. i closed every program i had running, and nothing stopped. i opened
task manager and ended every task running under my username, including
explorer (but not task manager of course) i then started to end some of the
'system' tasks untill the sound stopped. i then hit the "new task" button
and restarted explorer, and tried to play an mp3 that i know for a fact to
be good, and it did the same thing. i tried to end task everything agian,
but nothing worked. so i rebooted. i tried to play a video file. same thing.
the video itself played fine for about 5 seconds, then stopped playing. ive
had this problem once before, and i ended up reformatting because i couldnt
fix it. somebody please help me, i REALLY dont feel like backing up 30gb of
data AGAIN.