Sorry not much help. Well, not any really. But, do you know what resolution the final product should be when it does work?
As an aside, I went with my son to a well known outlet yesterday.
He came back with a 'shop soiled' machine of very hi spec and it included a HD T/V outlet. I would be very interested to know if I could download pics of this kind of quality, but if they couldn't be buffered and played in a contiguous stream, they would be worthless, cos the amount of data for HD is going to be vastly more than ordinary quality is would guess.
BTW, this top-end AMD with 4 gig and two 360 gig drives and a 64 bit Vista was a tad over 200 quid. Graphics had some dedicated memory and would do 'Video editing, but not Gaming.' According to the stickers on the case.