Here is a story from a former college of mine. It was at the time when small companies started to replace MS DOS PCs, mostly used for accounting, with Windows 95 machines. An accountant, who was not at work when the new PC had been installed (it was the first Windows machine there), called us and said that the mouse of her new PC was not working. "The arrow on the screen is not moving", she said. Our support guy checked with her the mouse connection, she rebooted the PC several times but to no avail.

So, he had to go to that place (about 200 miles away) supposing the mouse had malfunctioned. When he arrived he realized that the mouse was working just fine. She asked the lady to use the mouse. She took it in her hand, lifted it a few inches above the desk and started moving it left and right: "You see, I am moving the mouse but the arrow is not moving."