All right comtux i know exactly what you mean.
This happens to me in highschool as well at home. I get calls from people from my school asking for tech support.
One time my school even asked me to graph the state test scores from 95-2003. Anyhow heres how I do it dont set a fee. If their grateful theyll pay, if not give them worst service. Im sitting in computer class and have just been running around fixing bout 10 computers and a printer. Do i do it for cash no. Like open source i beleive some things should be free.
Anyhow my suggestion i did this to a couple of people who constantly ask for help. In order if they dont listen.
1. Hint to them like youve been doing, to make a switch.
2. I wrote a 10 page document on how to keep your computer clean, and included a cd of free windows software. For some that helped.
3. drop a custom live cd in their drive. I mean one that looks like xp and feels like it.
Also you can charge on say a monthly basis a number of 20 cents visits can add up so set a fee. Again i dont ask for money.
But she says dell and the microsoft support is shit point her here she will see people are willing to help.
I know alot of people like this there really isnt anything to do. My dad is one of them, he only sticks with windows because its the mainstream thing. The only real thing is to hold your breath and put down the fists and help them, or not.