I worked in the customer support division of a computer company for a few years, and I had to be prepared to answer all sorts of questions. Most of the people who call a customer support desk are needing specific advice for specific problems. I could usually walk those support customers through the process without much trouble. It was the ones who had no idea how computers worked in the first place who were the most challenging.
I think it's important for people to realize that a customer support service can only do so much for any customer. I could help someone reboot their operating system and wipe out a computer virus, for example, but I couldn't help them fix a broken motherboard. There are just some issues that go beyond the scope of a phone call to customer service or support centers.