dumboguy :
Sorry to hear all of you are having freezing problems too. I think i figured out my problem though. It was my damn Linksys WMP54G PCI Wireless Card. It doesn't have official Vista 64 drivers but alot of people claimed that if you use the generic drivers from the chipset manufacturer (Ralink) it would work fine. And it did sort of except it constantly froze up my computer! After swapping everything else around I figured I would try taking the WMP54G out and everything was fine. I ran games and DVD movies and it didn't freeze. Left it on all night and it didn't freeze. Today I decided to look for a wireless adaptor with true Vista 64 support which ended up being a major pain in the ass. Alot of them say they work even on the box but then there are no drivers available. I ended up buying a Linksys WUSB100 which quite honestly I don't even know if it has a true vista 64 driver but it works ok with the software on the CD it came with and the box claimed to work with Vista 64. I would really like to have a PCI adaptor instead but nothing for Vista 64 seems to be available.
I have linksys WMP300N wireless card and i didnt find its proper x64 driver too so i installed 32 bit driver for it. However that driver worked fine in my previous configuration and didn't make vista freeze.