-- (deprecated) Microsoft Windows OS (XP/NT/Vista)
---- Vista upgrade DVD is all you need.
encyclo - 5:13 pm on Feb 1, 2007 (gmt 0)
It may be all you need technically, but it's not all you need legally. The usage agreement will say that you need to own a particular Windows prior version, and the fact that the system can be bypassed doesn't make the installed system any more "legal".