DX10 means Vista
Unfortunately, to utilize DX10 you need Vista, at least at this point. I'm resisting that move until I have no choice. When I was buying my video card there were some of the 8xxx cards that were comparably priced to the 7900 I ended up with that would have supported DX10 but it just wasn't enough for me to see those blades of grass or crisper shadows to be forced into Vista.
Art