Vista MCE option

Hi all...

I'm trying to reconfigure my Vista MCE because I want it to pick up my
signal via S-Video. However, when I go to "Set up your TV signal" and go
through the options, it ALWAYS choose "antenna" as the TV signal. I remember
being asked what my TV signal was the first time I set up MCE and I remember
not unchecking "Configure my TV signal automatically". So, I think this is
now providing a problem.

I've tried reinstalling Vista, running the set up from the start via Tasks
-> Windows Media Center -> Run setup again.. but am having no luck.

Can anyone tell me how I can do this manually?

Thanks