Heads up: There's a very nasty computer virus going around. My mother got it the other day, and my work computer just got it (and her computer and mine hadn't shared anything so it had to have happened independently). It comes in through a web site you're browsing: you get a popup "warning" window that purports to be be from your virus checker (and it looks like an AVG screen), but it is in fact the virus itself. Then you'll see a window called "System Progressive Protection" -- that's the second level of the virus. My virus checker (MSE) didn't scrub it, but Malwarebytes did. Here's a very good tutorial page with step-by-step instructions on what it looks like and what to do to get rid of it.