I've got an HP XP pc that the cpu cooling fan runs on high as soon as the pc boots up. I pulled the side cover off to see if the fins were dirty but they are clean, plus it does it on a 'cold' startup. This started after I left it on all night a few days ago. I also noticed that it is slightly slower than before. I have run my virus scan and Malwarebytes but no change. I'm affraid there is a cootie in there somewhere, where do I start?