Comment Install Ubuntu (Score 5, Insightful) 823
I've had the same problem with my parents for years, going back home each Christmas to reformat windows and spending the week getting the configuration back to normal.
For the last 3 years they've used Ubuntu, with some problem with the printer the first few months, but now I'm just spending a few minutes pushing the "Upgrade Version" button instead of a total reformat.
They can check their mail/internet and you don't have to worry about virus/firewall, win-win :)