Comment Use Limited Accounts (Score 1) 932
At the risk of promoting my own work... I recently started http://netsafetyguide.com/ to address these kinds of situations. The goal of the site is to offer down-to-earth, practical news and tips about Internet safety and security.
One of the tips that you will find there is to use limited (non-administrator) accounts for the untrained/uninterested users. Moving my teenagers to these accounts greatly reduced my frequency of reformats.