I am running Windows Vista and windows media player 11 continuously gives me an error message if I am trying to play avi files or mpg files. Also some of the .dream files of animated wallpapers will not play but prior they were working. I have already installed all the necessary codecs to play this files but nothing is working. This all problem started happening after installing VLC player and even after uninstalling it I am still having the same problem. Can anyone please help?