On my MacBook Pro I suddenly can no longer play any videos done in windows media player. Up until a week ago I was fine but now I get a message saying, "This file may not play correctly because it was compressed by using a codec that is not supported". I have downloaded Windows media player anew and instlalled it but no good. I can take a video from my other mac that plays OK on it but when I put it on the MacBookPro I get the message. The video will play if I click OK on the message but there is no sound. Any suggestions???