No you did not! It takes time AND expertise to do those things. From an economic point of view, he has a reservation price for your services. If he didn't pay you $100, then that means his data and computer use are worth less to him than $100. Most people who use count on their computers will have a higher reservation price than $100, they need their computers. From your perspective, your reservation price for performing this work was at least $100, meaning you wouldn't perform the work for less. You would instead use your time on the next best alternative, perhaps studying, reading a book, working out.
One thing I have noticed recently is people expect computer service to be cheap because computers are cheap. While improvements in manufacturing have produced sub $500 pcs, no such improvements have been made to drive down the cost of computer servicing. To get where I am now with computers required years of self-study, experience, and application. There is no way in hell I would charge less than $100 to perform this work because of the costs involved to me.
Besides, people get what they pay for. I always laugh at people who tell me they can pay somebody else less to fix their computer. I always reply that I'm not sure they would want to pay less than my rate, because experience tells me they are going to get half-ass service in return and wish they had just paid me my rate in the first place.
