How much control do you have over the computers? Just the power to suggest whatever best practices they can understand? If you can, get them to stop using int

How much control do you have over the computers? Just the power to suggest whatever best practices they can understand? If you can, get them to stop using internet explorer, and stop logging in as root. Using a separate drive or partition for data, and making a practice of reinstalling the OS from the CD whenever they're infected can be good, too, especially if you can make a known-good image with all their applications and the latest patches. Successful security involves a certain mindset, though; and if the owner of the system isn't willing to adopt that mindset, your efforts will only go so far.