Is My 750i Dead?

[Scionix]

So, after ordering new ASUS P6T + i7 920 and learning the P6T was defective after two weeks of troubleshooting (FML), my old 750i is now having problems (of all the luck, right when I send the other mobo in for RMA). Basically, when I boot up, I get code 26, then 52, then 6F, then 7F. I looked those up in the manual, but the descriptions make no sense (test all memory above 1mb? What?). The beep code is one long beep, and two short beeps. I tried looking those up too, but google has failed me. If anyone has any ideas that'd be awesome.

CPU: Intel Q6600
GPU: GTX 295
Mobo: Nividia 750i FTW
Hard Drive: WD Caviar Green 500gb 7200RPM
PSU: Corsair 1000w
Misc: Sony Sata DVD drive, Sony SATA DVD Burner, wireless networking card, Creative x-fi sound card.

 

[mpilchfamily]

Check your RAM. Use Memtest to see if there are any errors.

 

[Scionix]

Check your RAM. Use Memtest to see if there are any errors.

I've tried cycling the RAM (using each stick, using each stick in each slot), but (really stupid question incoming), how do I run memtest without a backup computer? I'm posting on a friend's 5 year old laptop here >.>

EDIT: Should probably mention that when I boot with no RAM the mobo makes the correct really long "no RAM" beep, if that counts for anything.

UPDATE: Ok, this makes no sense. The GPU I swapped in earlier that didn't work, now works. I got into windows with it, win7 auto installed the drivers, and restarted. I had the GTX 295 in the primary PCI Express slot this whole time to see if I could troubleshoot it in device manager (where it was not showing up). At this point I'm pretty pissed, beginning to realize my GTX 295 has suddenly crapped out on me and I'm going to have to order a replacement (thank god for lifetime warranty). So, as I boot after the driver auto-install from Win7, it gets to windows, then when I try to log in the computer restarts. I take out my replacement GPU and just leave the GTX 295 in to hope something magical happens, and, no lie, the 295 is working now. I have no idea what happened, why it happened, how I fixed it, or anything else, I'm just glad it's working.

Does anyone have ANY idea what just went on?