My Parkinson's diseased father keeps screwing up the family computer...?

[Sakura Efreet]

I need some serious help. My father, who has PD, believes that there are people watching our computer. Because of that, he is constantly screwing with the security measurements. He caused the computer to crash (it's a Vista, not even a year old) in December and it had to be rebuilt.


Now, the internet is screwed up. Links won't work. Drop down boxes don't work. It refuses to automatically redirect to pages.

What is he doing to it? He refuses to listen to the guidance of his children (we are all grown, by the way). He screws it up late at night when no one is asleep. What can I do to try to get him to listen to his family in keeping the computer in ok shape?

Please note I can't edit questions either.