I had an old man that had trouble using computers, always getting viruses and what not. I installed Ubuntu to head off a lot of these problem but he refused to use it. He wouldn't even let it boot all the way up. He saw the splash screen and just turned it off. Next thing I know I got a request to appear in court in the mail and had to defend my actions to a judge that was just as ignorant of computers.
I actually lost the law suit but was able to get the court to agree that my punishment was going to be to set the machine back like it was. In my book that's not a loss. It's what I wanted to do from the start if he didn't like it.
After that I refuse to do anything for anyone that isn't paying me. No more favors, if any friends, neighbors or family want their computers fixed they can take it to a shop and pay to have it fixed.
Something a lot of computer techs need to learn to do. When someone asks of you can fix their problem recite, "I really don't know that much about computers."
I say this in the mirror from time to time.