One of our co-workers, a really smart one, had a customer who asked about backing up files. Co-worker told him to get an external drive, he bought one and left.
CW - Co-worker
CC - Crazy Customer
He comes back in the next day..."Say, there must be something wrong with that drive you sold me. (When their product isn't working right, it's always "you sold me" rather than "I bought".)
CW - Oh? What's going on?
CC - My printer won't recognize it.
CW - ...Your printer?
CC - Yes, when I try to scan a document from the printer into the drive, nothing happens.
CW - Well, what OCR software are you using?
CC - ??
CW - You are using a computer for this, aren't you?
CC - Uhhhhhh....you mean it won't work without a computer?
You guessed it folks, he had somehow connected the printer to the drive (Dunno which printer, but I bet it had a USB port) and was trying to scan directly from the printer to the drive.
CW straightened him out, suggested a professional scanning service for the 3000+ documents he needed to archive.