every time i get onto my laptop weather on line or not i get a blank page that pops up and im not able to do anything to get it off. control alt delete and i go to start task manager and it doesnt say there is anything running.. i tried going online with a microsoft tech and having them help me. they had me run a full scan for viruses. i did it and it found some stuff. fixed it but the blank page still comes up. whats going on and how do i stop this from happening?