Vista - Media Center will not launch

Hello,

VMC will not launch. I get no error or warning messages at all. The cursor spins for a second, and then nothing... I don't have a system restore point that I can try. I've looked at the file:

%windir%\ehome\ehsell.crash

after attempting to start VMC, but it is dated from yesterday. (I have rebooted since yesterday) It isn't updated when I launch VMC. I've looked in the Event Viewer under "Applications and Services Logs / Media Center", and there is nothing, not even any informational events.

I also looked at the "ehstart" service (Windows Media Center Service Launcher), and it is set to "Automatic (Delayed Start)". I manually started it, but it seems to stop itself again automatically. Maybe this is normal, I don't know... I also tried starting this service from a command line with: net start ehstart. It started fine, with no errors/warnings, but again when I go view the status, it is not running.

VMC has been working fine for a long time, until just 2 days ago. There are 2 things I did then:

1) I added an extender, from within VMC. It was working when I last quit.
2) I normally exit VMC by clicking the 'X' in the upper right corner, but last time I exited with "Task / Shutdown".

Any ideas/suggestions?

Thanks,
Mark