Windows Media Center

I have a windows xp pc with 3.0ghs cpu and 3gb ram. I'm trying to set up wmc for my xbox360. I'm also using a linksys WRT54G wireless router. The 360 is connected via an ethernet cable.

Here is my problem:

open windows media player > library tab > media sharing. If i click anything such as "OK", "Cancel" etc it will either freeze and i have to shut down via windows task manager or if i click "settings" it closes WMP out.

When i try to add folders or files to be shared on my xbox360 nothing loads and nothing seems to be stored and the don't appear on my 360.

It seems very weird to me and is there any help that can be offered?