Keyboard on the fritz...?

[DLzone]

I've got a large problem and would love it if someone could at least tell me what's going on becase as of now I have no clue and am starting school tomorrow!!! My computer has been up and running for over 6 months rock solid. Today while I was playing Doom 3 suddenly the character kept moving forward despite me not touching the keyboard. Thinking that this was odd I exited the game, but whenever I touched a key the computer made a large beep, basically a post beep or error. I restarted the computer, but when I tried to type in my password to log in, every time I touched a key I would get the error beep and the key would either not be entered or it would be a completely different letter. Eg. I type "l" and it would beep and either do nothing or enter "r." I tried swapping in a different keyboard and the problem still remains, which is now why I'm getting very concerned. My computer is protected by AVG Anti-virus and hardware firewalled. Here is a complete list of my computer specs. Hopefully someone has encountered this before and can help, it would be greatly appreciated.

Windows XP Pro
P4 2.4 @ 3.0 (Have tried bringing it back down to 2., didn't help.)
Asus P4P800
2 x 256 Corsair Cas 2 PC 3200
Radeon 9800 Pro
Creative Audigy
Liteon 48x Cdr
Lg 4x Dvd+-R

edit: One more note, it seems to work just fine while in the bios.

 

[DLzone]

Ok, it gets stranger. I restarted the computer and then suddenly I got an error that the bios was corrupted and I needed to put in the recovery disk. Restart again it posts and then I get an error that there is a critical file missing in the Windows installation. I restart again and I try and go into the bios but it freezes every time I try. Restart again and then I get a keyboard error at post press f1 to continue, it continues on it's own and the windows safe mode selection come up, but the keyboard is non responsive so I can't do anything. I reset again and get into the bios, set everything to default and suddenly windows comes up and everything is back to normal. No errors or anything and the keyboard works fine. This is quite possibly the strangest experience I've ever had with a computer.

 

[Cerb]

As always: any bulging caps? This sounds very much like such a death, where things go bad quickly and only over a few restarts. Also look for burn marks around the voltage regulators.

It's either mobo, CPU, RAM, or PSU.
The chances of RAM or CPU just up and going back w/o major overclocking: nil.
The chances of the PSU doing that: pretty slim.
The chances of the mobo doing that: slim, but more likely than the rest.

Good luck, and keep up posted. I start in two days, and I'd be in deep **** if I couldn't have it fixed up by the second week.