And you don't reformat a drive, you format it, unless you've changed the filesystem. The prefix re is vastly overused, just like pre.

Never once had a problem that I could trace to some security patch I installed. But then I am sure to avoid programs prone to having problems associated with them... So no Internet Explorer, Outlook Express, Office, Windows Media Player, file sharing programs, etc. I also use a custom built system, with every part researched fairly extensively, so that I could ensure only quality components were selected. I've had nary a problem at all since I started using alternatives to Microsoft programs as much as possible.