Vista is just a resource hog.
How do I know this, from the Vista BETA 2 DVD our school got. Solitaire, of all the freakin' programs, used up 48MB of memory!
Now, why in the world should SOLITAIRE use up that much memory? Answer, it's a resource hog.
The system requirements are high for a reason, because so much useless crap is in it!!! Stick with XP, no need to get Vista, just a waste of money...