Starting To Feel Fedup

I am starting to feel fedup always doing technical support for free. I am excluding office work here. My mum's friend always calls me when his laptop hit error. If I want, I would like to charge a fee for driving there and also fixing the problem. But the thing now is I am always doing this for free. I guess if it is other people, they won't give a damm about others problem. Maybe it is time I learn how to avoid this type of help :P