Alright guys I've sorted out my troubles. I was able to pretty much
rule out everything except the mobo as not working, so I bought the
mobo kony suggested, I just installed it, and I'm now running memtest86
and not getting the errors.

Windows isn't booting, mind you, but that's a Windows driver issue, not
a hardware issue.

Grrrr, stupid Windows. It should be able to hot-swap mobos.