I'm really not trying to one-up anyone's tech support stories, because there are some real gems in here. However, I once looked on in equal amounts of horror / amusement as an end-user that I supported attempted to set up her new (evidently first ever) PC, and couldn't figure out why the "foot pedal" wasn't working. I realized that she had connected her mouse, put it on the floor, and was attempting to use it like it was a sewing machine or something. I had to excuse myself, find the nearest restroom, and laugh until every orifice in my body was leaking. At least I was in the right place for that kind of thing.