AMD X2 3800 Crashing my PC

[Nitecon]

Recently purchased a new AMDX2 3800 to replace my AMD64 3000.

Never used to have any problems with the 3000, everything ran smoothly.

But when I installed the X2 3800 my PC boots up Windows,, but after about 5 mins it will freeze, reset and reboot Windows. Then I get a Windows error message saying that there could be a serious fault with my Motherboard, Power Supply, RAM or a 4th component that I can't remember.

I'm slightly worried, but this just does not occur with my old CPU.

I've checked the BIOS, temperatures, everything is fine in there.

I'm currently running the AMD64 3000 right now and have not had any glitches whatsoever.

SPEC:

ABIT Fatality SLI
AMD64 3000
4 x 512mb Crucial RAM
BFG 6800gt
Enermax 485w

Running the most recent BIOS, and Windows fully updated.

Help me out!

 

[Nitecon]

Thanks for the tips, I'll try them when I get home from work.

Incidentally, I've been reading about these hotfixes and optimiser driver things for Dual Core CPUs, do I need to install any of those?

If I do, do I install them before installing the new CPU? Since my Computer is bound to crash with the new CPU in whilst downloading the drivers.