Like a lot of admins, I've found that terminology can cause all sorts of problems. One common error is for users to use the term "hard drive " to mean the pc case and everything inside it.

I got a call about a graphics problem, with the monitor just show a screenful of colorful lines. I told him to bring the pc to me, as I'm now a semi-retired invalid and only work from home. He asked if I only wanted the hard drive. I just assumed he meant the case etc. I said yes, don't bring your mouse, keyboard or monitor.

I was a bit confused when he turned up at my door with a small cardboard box and asked how long it would take to fix. I opened the box and there was the actual hard disk drive from his pc. One of those "A little knowledge can be dangerous" situations. It taught me that a little time spent making sure we were both on the same page can save a lot of time as well as saving both of us from feeling like idiots.