In the past when installing an upgrade version of Windows it meant having your original disk handy to prove that you were REALLY eligible for an upgrade license. What this meant is that if you wanted to follow the advice of MOST in the TECH community you could do a clean install. That’s right, wipe the disc and start from scratch, provide the disks when asked and then the installer would be on it’s way. Well, sorry, the joy is over. (Actually… there wasn’t a whole lot of JOY in it… but… it’s now worse.) Now, with Vista, it is required that you have the previous version of Windows that you are upgrading installed on the disk.