My grandparents paid to have this installed on their new PC today. It sucked. It was *constantly* using about 30% CPU usage on a Core i5. And parts of it just plain didn't work. I got them a refund and uninstalled it.
Well I asked my uncle who designs security software for capitol one. He said if you want a free Antivirus webroot is a good one because it works well and is light on your computer.