Can't help with uninstalling WMP but have a suggestion for a player. The latest version of Cowon Jetaudio is pretty comprehensive to say the least. For the record, I run an earlier version on Win98 without probs. Its freeware downloadable from
http://www.cowon.com/eng/product/jetaudio5/about.html
Mind you- I still have a soft spot for my l'il ol' Winamp.