Rivets, you can expecta a release candidate version of 7 in a month or so. I am certain that version will find it's way out if you are comfy with bit torrent downloads. I have run 7 from build 6956 to build 7057 it's good. it's real good.
FWIW I have repeatedly activated the same copy of xp when machines have died, mobo's blown up etc. For the hell of it, I've rebuilt on the original disc & always been allowed to do so by ms. Maybe worth a go?