If you want to set up a MCE but without a tuner card installed and configured then the following registry hack will help:-
Start>Run>regedit>OK
Now navigate to the following location:-
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\Curr entVersion\Media Center\Settings\TVConfig]
"iVideoSource"=dword:00000002
"iBroadcastStandard"=dword:00000001
"fHasSTB"=dword:00000000
"fHasDVB"=dword:00000000
"Version"="65537"
Note- though the system will think that there is a TV Tuner card but you can't watch any TV show (because it's not possible at all),but you will be playback videos ,mp3's ,online spotlight etc....