Computer Randomly Resetting Itself

I am running Windows XP. Of late, My computer has been rebooting itself randomly within about 3-5 minutes of being turned on. I've been searching around for likely causes, and the "SASSER" virus seems to be the cause best fitting the symptoms. When I run windows task manager there are several copies of 'svchost.exe' running all at once. I have tried ending these processes and using the 'shutdown -a' command in the windows command prompt when the infamous "your computer will shut down in 60 seconds" message appears. I can get my computer to stay alive for a while longer than it normally would, though whenever i try to open a web browser, or run my antivirus, the computer will reset. I have also tried sending over a disinfecting tool from another, operational, computer on the network, but network neighborhood claims sed computer is offline. Is there an easier or better way i could go about fixing this?

I apologize if this topic is misplaced, I am not familiarized as to how the Q&A system works here.