I'm Blue Screening with Stop Code 124. Here's what I've done:

1. CLEAN installs of XP and Vista.
2. Turned off "extras" in the BIOS like cache.
3. Replaced the motherboard (Through BFG's RMA)
4. Replaced memory (with wife's)
5. Replaced video card (with wife's)
6. Replaced power supply

Would a bad CPU cause this issue? All temps and voltages are dead on in the BIOS and with Everest. This is driving me nuts.

Quick Googling tells me this could be a sound card issue. Remove your sound card (or disable the onboard if that's what you're using) and see if the problem persists.

Also...list your hardware specs. Motherboard, CPU, RAM, video card, etc, etc...everything that you know or can find out.

Figured it out... it was the CPU.
My wife and I have the same system setup (It's how I convinced her to let me have mine).
I went ahead and switched our CPUs and her system started having the issues.
Thanks anyhow... I need to RMA this Intel CPU.