My WMP plays 16:9 fine. You do, of course, need a wide screen monitor or TV to avoid the black stripes at the top and bottom of the screen and you must have a 16:9 video. Showing a 4:3 video on a wide screen will give you the black stripes. If you type "16:9 aspect ratio" without the " into the search box in the help files it will come up with easy to follow instructions of how to edit the aspect ratio manually if you are having trouble!