HELP System Shutdown Virus

Can somebody, anybody help me please. My dell pc running windows xp service pack 3 is infected with a virus or something that freezes up my computer, the mouse and the keyboard with system shutdown in 60 seconds. I have tried to boot in safemode to no avail, it freezes. Is there anything that I can do to get control again. Do I have to take the drive out and put in another machine or take somewhere to get cleaned, I read somewhere about a reboot disk or ISO and torrent sites (clueless) Any suggestions, anything I am so seriously desperate but I don't know the first step in trying to get it back. This has been going on for days and I need some serious HELP. I have search the forums and the net but have not found this particular situation. Malware and superantispyware are installed on the pc.

PLEASE help me this is my second posting. Thank you,