I second that. There really is an imperative to maintain a pc, just as you would a car or your house. Although I've never had a problem booting the house.
I have a friend who surfs all day on a completely unprotected laptop & surprise surprise, it's infested with all sorts of horriblemess. She asks me to fix it regularly & I've now refused to look at it anymore until she puts antivirus on & turns on the firewall.