Yes, I neglected to say what OS I was using. It's XP Pro. Someone had mentioned doing a virus scan, but I'd been doing that all along. I have Norton AntiVirus on the computer, and it updates regularly. It never found a virus. However, not too long ago, my teenage son, who had been downloading music, found a virus in a music file. Why the Norton didn't pick up on that, I'm not sure. He's eliminated the virus, so I'll have to experiment with the updates again to see if I continue to have the same problem.