|If the hard drive is not showing in the BIOS you may need to send out to a recovery service. Very expensive.|
Lesson learned concerning backups.
Feel the hard drive while under power to determine if it is rotating. If not then a gentle tap on the side of the drive MIGHT get it going.
More likely cause is bad electronics on the drive. Only fix for that is swappin out the PCB on the drive. Problem is they change those very often, so even a PCB off the same model drive may not work.
I assume you have verified the data and power cables are good?
Also verify the IDE contoller is Enabled in the BIOS and is working. If you have TWO IDE controllers switch them to see.