Just install it from scratch on the new machine with the same key, copy your files over and delete the source installation. Don't ever move it or move disks - it will shit a brick.
Did I say that I had the professional upgrade! If I tried to do that, it would moan that there wasn't a copy of Windows on the other machine that I was trying to install it on. Even though when reading the license - I am entitled to move it. I guess there's always the hotline...
The other point that I raised was that I suspect I'd loose my media centre upgrade - well I assume I would, which frightens me a little, as it was the main reason for grabbing Win 8 in the first place. But I digress.
