Nam,
My first question would be are you happy with Vista? If so no real need to upgrade the OS.
Next yes you can upgrade Vista, but it is highly recommended to do a reformat and a full install.
Yes Win 7 should run Xp and vista games
Win 7 like Vista comes in 2 flavors 32 and 64 bit. No real reason to go 64bit unless you
want to use more than 4 gig of Ram, thats all the 32 bit will recognize. Still as of today
as far as I know there are no 64 bit applications yet. As far as game speed I have seen
reviews comparing 32 vs 64 bit, some were a bit faster on 32 others a bit faster on 64.
I currently run Vista 64 home version ( got it for 15.00) I have alot of stuff turned off
because I use this OS only for Gaming. I have another bootable drive that I still
use win2000pro on for my home banking, internet ect.
I will upgrade to win7 ONLY because soon I will be able to buy it through my company
for 10.00 and thats the only reason. I may install a 3rd bootable drive to put this on to see if I even want to keep it.
Bottom Line if your happy with Vista save your money. Now if you still want win 7
you can do a full install with an upgrade version( upgrade version is cheaper).
I can send a link if need it with instructions on how to do this.
My vist64 is an upgrade disk, but I did a full install with it. And its all legal.