Okay you embedded WMP on a webpage how does that make WMP open when all you have is a link to an avi, mp3, mpg file? You may not get what I am saying. I am going to use VandalL's avi from about for example:
http://www.kberg.ch/kcr/avis/r83.avi
I want to be able to click that link and have it open and download with WMP instead of downloading and the possibly open in WMP. As far as your "sourcecoode" goes If someone running did not have a fairly modern version of WMP installed, your avi would not show on the page. Linux users, for example, would not be able to see the avi. An animated gif might be a better way to go.