How do you know it was not an end-user error on the build or installation? I don't see how a CPU mfg. can be at fault for an unstable system, unless you have faulty hardware.
I second the reccamendation of a complete reformat and reinstall.
A few things to check for... run a memory test (I.E. Memtest86+) to see if it is a memory problem. What RAM is the system running on?
Somewhat unrelated, usually, but in my experience, video card drivers that are bad, improperly installed, etc. can crap a system out anytime.
You're the guy from that hamburger train, right?