Okay, this is getting annoying now.
I played with the 5V Jumper and set it back to default, and my computer turned on again. I lowered my RAM overclock so that it would run stable at 3.2V (it used to be at 3.3V), and for two weeks now, it was running VERY unstable. Random reboots and BSOD's every now and then, but it worked, for about two hours at a time. Today, it started getting so bad that it would BSOD a few seconds after I got into the Windows user selection screen. I ran Memtest86, and found some errors in both memory modules at every setting possible.
I went to a nearby computer store, and bought some crappy Centon value RAM (all they had was this, Corsair VS, which has known issues, and $350 Corsair XMS, which is way too expensive). I put this in, and ran Memtest again, this time with no errors, so I tryed to boot into Windows, but got the same BSOD at the user login screen.
I don't think RAM is the issue, and I was only using 1.55V max for the CPU, and was getting great temps (high 40's at full load). My PSU voltages are fine, I just got 11.95V, 4.97V, and 3.31V with a multimeter.
What is the problem?