OK so yesterday I turned on my computer and saw a nice juicy flagrant system error, complete with blue screen. I realized that I hadn't reformatted my computer in about a year and a half. I don't have scheduled reformats, but usually the spyware weighs more than the OS and the Norton hits the fan every six months. So, how often do you guys reformat your hard drive? Just curious. I've heard some people say they do it every week.