I don't know how else to describe it. At least once a day, my main PC will get stuck in what I can only describe as having the down arrow held down. As in, anything you try to do acts as if the key is being constantly held down. So you can't even use the Start Menu, let alone type anything. The only fix is a reboot. I thought it was the wireless keyboard I was using, but I have since swapped it with a normal one and it still does it. I have scanned for viruses and nothing was found. Any ideas?