If you have issues with your EPG guide, here are the steps to reset your Media Center TV settings to “factory” default.
WARNING: By doing this, you will lose your TV configuration including scheduled programs (but not the recordings, of course).
Open Windows Task Manager
Make sure the mcGlidHost.exe process is not running (Kill the process if required)
Rename (or delete) the *.db file(s) under c:\ProgramData\Microsoft\eHome to something else (Note: My file is called mcepg-2.0.db but your file might be called something else and there might be more than one.)
After this, you can open Media Center and run the TV setup wizard and setup your guide as described in the getting started
guide on the website.