Yeah, I think based on what you have, where it will work in safe mode, which doesn't require much video card usage, but it won't run normal mode, that it is the video card... Best thing to do is try another video card. Doesn't have to be good, just enough to work with Vista.. and if it works, then we (you) found the problem! But you probably know this though... Just suggesting what I would do, look at what the problem is, and then just try replacing the most likely parts, and working my way down, until it worked again, hopefully never having to try the motherboard!