I'm a tech support engineer for a software company. I had a guy call up rather annoyed that the disks we'd sent him containing the latest version of our software didn't work.
Customer: "The install fails half way through. I tried several times, and it always fails at the same point."
Tech Support: "Did you see any kind of error message?"
Tech Support: "What did the error message say?"
Customer: "It said, 'Please insert Disk 2.'"
Tech Support: "Have you got another disk there?"
Tech Support: "Is it labelled 'Disk 2'?"
Customer: "Yes, it is."
Tech Support: "Take the first disk out, then insert that disk into the drive, and click 'OK'."
Customer: "Wow, thanks! That's fixed it. It's installing now. What was it, a faulty disk or something?"
No sir; the Problem Existed Between The Keyboard And the Chair.