James can't find his Media Extender software anymore, and found out it's not being supported anymore. He was using it to stream to his son's Xbox. There are other things, such as Plex, that will do this same thing. Plex is even based on Xbox Media Center so that could be a good option.
Lukestratton from the chatroom says if he installs this hotfix rollup at http://support.microsoft.com/kb/900325, it contains Media Extender.