Computer Problem

I was having trouble with my computer. So I called Bob the computer guy, to come over. Bob clicked a couple of buttons and solved the problem. He gave me a bill for a minimum service call.

As he was walking away, I called after him, "So, what was wrong?" He replied, "It was an ID ten T error."

I didn't want to appear stupid, but nonethelessinquired, "An, ID ten T  error? What's that, in case I need to fix it again?"

The computer guy grinned.... "Haven't you ever heard of an ID ten T error before?"

"No," I replied.

"Write it down," he said, "and I think you'll figure it out."

So I wrote out....   I  D  1  0  T

I used to like Bob!