Ask HN: How to protect family members from malware?

My Dad uses Win7. He is a little too active on Facebook and used to install browser plug-ins and "free applications" without really considering the implications. I have been able to gradually wean him off this habit. But, his machine continues to be infected with malware. I finally got him to install NoScript on Firefox in the hopes that it would reduce such incidents. How do you protect your family online?