Windows won't load and keyboard stopped working

[splashpot]

PC I just built. Worked fine for 2 days. I'm browsing with Firefox, just looking for my usual programs to install, and FF quits. Ok, no big deal, I fire it up again, browse for a few minutes and it happens again. Then all of a sudden , I get a flash of a blue screen(too quick to read anything), and it reboots randomly on it's own.

5 minutes later, it happens again. Only this time, I can't even get into Windows. It's at a screen where it asks me if I want to boot in safe mode, last known good config, start windows normally, etc. It also has a countdown that says it will load in 30 secs. Only when it gets to 0, nothing happens.

In addition to all this, my keyboard only works on the very first bootup screen (called the POST screen?). After that screen, it stops working. No light when I press the num lock button. I can get into the bios no problem, but if I try to go anywhere else, it stops working.

This has to be a hardware problem, right? Mobo? HD? I've barely installed any programs on it. I figured just to make sure, I'll reformat and reinstall windows. Only I can't because when I try to boot from the DVD drive, the keyboard freezes and I can't choose what to boot from.

Is there any way to figure out what my problem is?

[splashpot]

Oh yea, my specs.

AMD Athlon 64 X2 5200+
GIGABYTE GA-MA69GM-S2H Motherboard
COOLER MASTER Hyper TX2 CPU Cooler
EVGA GeForce 8800GTS 320MB
G.Skill (2 x 1GB) DDR2 800 (PC2 6400)
FSP Group (Fortron Source) 500W Power Supply
Seagate Barracuda 160GB 7200 RPM Hard Drive
Sony NEC Optiarc 18X DVD±R DVD Burner
Windows XP Pro

[splashpot]

Ok, I found an option in the bios to "enable" my USB keyboard. Weird that it worked before. So with the keyboard working, I tried booting in safe mode and I get this message:

multi(0)disk(0)rdisk(0)partition(1)\WINDOWS\system 32\ntoskrnl.exe

I'm currently trying to google ntoskrnl.exe to figure out what that is.