Yes, you shouldn't have ordered the Windows 7 Upgrade. It requires that you have a previous version of Microsoft. You can most likely cancel your pre-order. Just contact Amazon about it and tell them that you need to cancel it, and they should refund you the money. What I was trying to say last night, was to get Windows 7 RC, which is the release candidate, and you can use that fully functionable up until spring next year.
The windows 7 RC has nothing to do with the Upgrade that you pre-ordered. If you google Windows 7 RC you'll come up with this
. Just read that and you can decide then. But if you used that until it came out, it would be easier than getting an upgrade from vista, because you'll receive an upgrade copy, which from what I know requires you to have previous versions of windows installed and it makes it harder to reformat than just popping a full windows 7 cd in the drive and going from there. Also you'd have that extra $100 lying around until then.