Shutdown prompt keeps popping up?

[Fred]

Windows XP service pack 3 installed. Prompt for shutdown keeps popping up
while I try to do work. Makes no diff. what I am doing I have to hit ESC key
to drop prompt off of screen. Sometimes it comes back within a few secounds
other times may take an hour to come back u.

 

[Leonard Grey]

Malware?

 

[Fred]

Not sure I have a number of malware progrmas to remove thought all was good
but this keeps popping up.