Uninstall WMP 11. Then click on this link to install 10.

http://www.microsoft.com/windows/windowsmedia/player/10/default.aspx

FYI: There are other Media players as well Real, Quick Time, DivX. You could make one of these your default player instead of WMP. I like Real, you can download videos with it. Irt also let you run WMP and Quick Time vids in it to, sort of an all in one. Forum untracked, your on your own, see ya.