I have Windows Vista first of all

My question is; when i move a window or scroll a web site there is some distortion in my audio be it winamp, windows media player or youtube. the song slows down some and gets choppy. i changed the master volume of the computer and updated my driver the distortion is still there. i used a second set of speakers and its not a problem with the speakers. any help would be greatly appreciated.

Also I'd like to add that this problem just started. The computer has been processing finely for several months.