Ever have issues with duplicate lineups? Duplicate channel listings in your guide? Or just overall quirky issues with your media center? I found a quick and simple way to reset it to default.
All you need to do is go to the C/ProgramData/Microsoft/eHome folder and rename or delete (I would advise rename) mcepg2-0.db and the folder mcepg2-0. Then just restart your Windows Media Center services. The way I went about it was through safe mode, as I could not do it while the system was running within windows itself. Once you do that, reboot, and you have a fresh Windows Media Center copy. If you need to re import your recordings, now is a good time.