If you want to reset WMC back to day one and start over here's how.
Goto Control panel, Folder Options, View and select 'Show hidden files and folders'
Save and restart pc in safe mode by hitting F8 at boot (this is so WMC services are not running)
Navigate to C:\Program Data\Microsoft\ehome
delete folder mcepg2-0 and file mcepg2-0.db (this is existing WMC data)
restart pc normally
goto Folder Options and re-hide hidden files and folders
start WMC and click live TV setup