Yes, you can do a full install from an upgrade disc.

i was reading an interview with a dude that used to work for microsoft on the windows projects until he switched over to helping with Valve and Steam ,,and even he said it was the worst and most useless OS..most un practical.

He eve went so far as to say sadly enough that he would use it for gaming but only after he spent quite a bit of money upgradeing his system in order to use it for gameing ,,but when it came right down to it he would use a mac for anything else

and here it is ::::

Newell: Microsoft has so many problems with Vista; I wish they were focusing more on the thing that runs on hundreds of millions of PCs rather than six million proprietary clients. Vista really shows a lack of focus on making a better consumer platform. I came out of the Windows group, and right now, I’d go with a Macintosh as being a better solution for most consumers than a Vista-based PC. It’s shocking to me. If you’re an XP user, you’re going to be more comfortable upgrading to an Apple than Vista.