When people act like children, treat them as such. Patronize them and berate them while explaining how computers work on the most fundamental level. If they have the gall to talk back and insist they are not a child, then leave them high and dry to deal with their issues. Ideally you leave the fix halfway finished when this happens.
If they get mad continue telling them that they're stupid for not learning how to use a machine a 10 year old child can use and do not treat them like adults until they begin to act like them.