As silly as this sounds, watch him on a typical surfing night and see what he does.
I mention this as I had a friend whose computer got infected with a virus, and as he was debugging the machine, his daughter was watching over his shoulder.
A box from Norton popped up warning him that some attachment was a potential threat and was he sure he wanted to open it.
At this point his daughter chimes in and says "That stupid thing, again! I had to disable it so I could read what my friends send me.. "

Poor guy..