I have added an IBM 80-GB slave hard drive to my rig and it doesn't show anywhere: not on the XP or Me partitions, nor in the BIOS.

I have had this same setup with these drives before, working fine. The only difference is that this time the slave HDD already has stuff on it I really need to keep, instead of being "blank". These are media files that are too big for CDs.

The BIOS HDD detection setup is set to auto, and I restored all setup defaults.
The primary HDD is at the end of the 80-wire IDE ribbon, and the slave is in the middle.
They are jumpered correctly, master and slave, and the power connections are in good and tight.

I have tried resetting the BIOS jumper on the mainboard.
I have also tried disconnecting the slave HDD, restarting the PC a couple of times, and then reconnecting it and restarting to see if it was detected. No dice.
Just for fun, I booted with a win98 floppy. I couldn't find it in there, either.

I can't use my Ghost partition backup, because that is the drive it is on.

Besides, I don't think restoring a Windows partition would help, as the BIOS doesn't see the drive.

Any suggestions?