See that chart up there? That's a beautiful visualization
of a dozen folk models surrounding the idea of home computer security, devised by Michigan State's own Rick Wash. To construct it (as well pen the textual explanations to back it), he interviewed a number of computer users with varying levels of sophistication, with the goal being to find out how normal Earthlings interpreted potential threats to their PC. His findings? A vast amount of home PCs are frequently insecure because "they are administered by untrained, unskilled users." He also found that PCs remain largely at risk despite
a blossoming network of preventative software and advice, and almost certainly received an A for his efforts. Hit the source link for more, but only after you've spiffed up, thrown on a pair of spectacles and kicked one foot up on the coffee table that sits in front of you.