What does it mean when your computer says hard drive not found?

Answer 1

The best way, I think to answer that is to define what a computer (or in this case the motherboard of the computer) needs to find or identify a hard disk.

A hard disk needs a power source, a connector to attach it to the motherboard, and a controller to talk to the microprocessor of the computer. If any of these things fail the hard disk will not function and the computer will not recognize it.

In general when you see the message "hard disk not found" its because the computer can't recognize the hard disk. This can be from a bad cable (that connects the hard disk to the motherboard), no power to the hard disk, or a failed controller. In my experience, its usually a bad cable but there are times when the hard disk itself will fail. Generally, hard disk cables are far more fragile than hard disks.