I have this list of things that home users can do to be more secure. One thing I might try to fit in there is to suggest that home users figure out how to install their Operating System.
Now, this may not be about trying to teach someone the nuances of a reinstallation, especially that they should have their data backed up, accounts and software licensing information stored separately, and a list of everything they had installed or need kept available for a reinstall. However, I do believe that one problem people have with working on their computer is a simple lack of exposure to the reinstall process (or someone/someplace that can do it for them). A reinstall is not typically something people do since their computers come from Dell or Gateway which happily does the work pre-ship. But the Internet can become a safer place once people get used to the process of a reinstall or where to turn for help if they decide to do a full reinstall.
I might consider this a half-step since it might be one of the scariest things the average person will do with their computer. Trust me, people are more scared about a reinstall than they typically are about installing all sorts of random programs on their system. Sometimes they are completely worried about losing their years’ worth of settings and small tweaks and the position of their desktop icons. However, regularly performing an install or just knowing that it is not all that bad an ordeal will help in being smarter about their computer use. If nothing else, befriend a local support guy, your local Geek Squad, or become familiar with the ability of your provided Tech Support.
I liken this to having a backup solution in place. But how do you know the backup solution is working or how much it is backing up or how to work a restore in the event of an emergency if you’ve never done a restore from it? An emergency is not the best time to do a restore for the first time.