Which model laptop ?
to check temps download speedfan from click here ,install and run, check the temps when you begin to run a virus scan and as it continues, note the highest temp recorded. on my FS Amilo 7830 I've had the temps reach 65c (midsummer, running [email protected]) without any problem occurring.
Right click on your desktop then properties. What options do you have set in
display properties > screensaver > power ?