“Any noise her laptop made sounded like something between a Dalek and a thrash metal singer”

Iwas installing a new network printer on a client’s computer when the conversation turned to car mechanics. This gentleman, I should explain, was one of the staff in the office where I was working. He seemed interested in my job as a roving IT engineer, solving problems for small businesses and individuals, and asked me what part of the work I found the most difficult.

After some reflection, I came up with three words: “weird software problems”. Sometimes, I explained, a computer could misbehave for no apparent reason; the hardware tests okay and my usual diagnostic tools suggest no faults. Yet the machine does not work as it should. I looked away from the monitor and to his face. He still seemed interested. Either that or he was good at poker.

Time to reach for a car analogy. I explained that when a garage receives a poorly running car, the mechanic will look to the engine or fuel as the most likely reason for the fault. With a computer,