Re: For what it's worth
"Speaking as someone who has been called upon to fix friend's PCs, I sometime think it would be nice if every consumer PC sold came with external HDDs and an image back up system by default. :)"
Two problems with that approach.
One, sleeper infections exist that stay quiet for a while so as to get themselves INTO backups, meaning restoring the backup just gets you infected again (since you probably won't know which files contain the payload and a smart one will hide in multiple locations, including WITHIN legitimate programs).
Two, you overestimate the intelligence of the average computer user. Given an external hard drive, they'll probably find some way to break or usurp it. Didn't the late Terry Pratchett write once that if there was an End of the World button, the paint wouldn't even have time to dry?