My computer will not boot up. It goes into the Safe Mode screen and no matter what I choose (Safe Mode, Safe Mode w Networking, Safe Mode w Command Prompt, Last Known Good Configuration, or Start Windows Normally) it reboots and goes back into the Safe Mode screen and does this repeatedly until I switch it off by hitting the power button. It did not have any problems shutting down prior to this problem, I don't know what would have caused it and I have no idea what to do to fix it. Any help would be greatly appreciated.
I am running windows XP SP3.