Problems with virus thru messenger

[razazteca]

I believe that my current problems with computer crashes are a result of a virus that was passed thru the messenger. Whenever I try to use a program like AVG or Spybot or Pest Patrol it freezes on me forcing me to reboot. If I try to reboot it will sometimes give me a error messese "Cannot find bootdisk, please insert disk in drive A:" or something similiar but if I turn it off for a few minutes it will be ok.

 

Is there a removal tool that can help me?