insert CD/DVD and see if the problem still exists. if it does- then it's most likely some sort of hardware problem. if it doesn't, then it was windows.
if none of this works, i have a question: have you put any Sony audio CD's in ur drive lately? there's a hidden copy protection program on some sony CD's that can cause <some> of the symtoms ur describing.
report back here with ur results so we can futher troubleshoot the problem.