I have a frustrating problem: I load Norton AntiVirus & it won't scan my system. I select "Scan for Viruses" and the Scan Progress window comes up but dissapears almost instantly. I cannot figure out why. I've tried completely deleting the software, reinstalling and still, I have the same problem. I've run all sorts of checks on my system and can't find the problem. I looked on the Symantec site and can't find a thing. What do I do?