Automatically Restarting and No Safe Mode

I am writing here from another system as my main PC has caught something nasty and is not working for squat.

Ok, I was getting pop-ups for yet another fake anti-virus warning, so I guessed I had gotten a nasty malware thing as I have in the past. So, I run my antivirus/malware removal software (SpyBot SD), and it found a boatload of junk and supposedly fixed. I rebooted and now it restarts itself approximately 10 seconds after it is finished booting up. over and over it does this.

I try to restart in safe mode, doing the usual F8, and select the option for safe mode, and it just brings me back to that options screen. It matters not if I am selecting Safe Mode, Safe Mode With Networking... the only thing it will boot back up with is normal standard mode. And of course as soon as it is done booting up, it restarts itself. I cant run any programs on it, it does not stay up long enough for me to even launch a browser.

 

I am running Windows XP Professional