Xpress Pro doesn't work with Vista, but for $495 you can upgrade it to Media Composer 3.5, which does run on Vista and is about 1,000 times better than Xpress Pro.
Or, if you're determined to throw it in the trash, PM me and I'll pay shipping if you want to give it to me.
I have 1 copy of Media Composer already and yes it is very good. I cut a feature film on it over the last 8 months containing 74 P2 cards and the system never once had a single error, never crashed, nothin!
Cheers to that Avid!