I've had this problem since feb when I bought Ultimate upgrade. Here's my system specs, understand that regardless of what application i'm using it will freeze. From email, to gaming, to media player.
Amd Athlon 64 4000+ San Diego cpu
Gigabyte GA-K8N51GMF-9 motherboard
2 gigs ddr400 pc3200 memory (4x512)
eVGA 7600 GT KO PCI-E video card (onboard gpu is disabled in BIOS)
ATX-520W power supply
Seagate barracuda SATA2 /300/ 16mb cache 320gig hard drive
LiteOn 20x Dvd writer (ATAPI/E-IDE interface)
All drivers are current as are BIOS version for mobo, i'm on my 3rd install and MS has gone so far as to send me a free replacement disk believing that the original upgrade could've been corrupted. My most recent chkdisk /b has come up clean. On a clean install w/ no 3rd party applications aside from network drivers, etc... it still crashes. I've run the windows memory test and also memtest86 and come up with nothing? Hardware? or just a case of the heebie jeebies? BTW, this is not an attempt to highjack the thread. Just trying to continue the thread. My system freezes exactly the same way. You have to hard shutdown to restore function. Thanks for any and all replies.