You probably need the right CODEC (coder-decoder). Get K-lite codec pack. !!!It might fvck up your WMP!!! So use the mediaplayer classic provided, instead. (I'm having issues with WMP10, for some reason it isn't auto-getting media info when i pop in a legit CD I bought at the store. And it freezes from time to time. Micro$oft! Yeesh!)
http://www.codecguide.com/download_kl.htm
"standard" package should do ya just well.
Hope this helps. I have a ton of wsop and wpt movies. like 15GB or so. Download emule (
http://www.emule-project.net) first and PM me, second. (if you're interested of course)