Since the drive is missing in the BIOS you need to fix that first.
"Is my backup drive a lost cause?"
Given only this information, yes. But do check your connections, the drive is spinning and that you used the proper IDE 80 conductor cable with the jumpers on CS.
Bob
Operating System: Win XP
Memory 512 KB
120 GB Master drive /60 GB slave both unpartioned
4 yr old Custom Built computer
I am experiencing this problem with my slave/ second hard drive. Last night while surfing, my system just froze. It has never done that except on hot days. So when I turned if off and then reboot it went into CHDISK mode. I let it do that it says it found no errors but ut also doesn't seem to allow for my Anti Virus to complete it's scan task. So when I turned it on this morning it did the CHDISK screen again then it finally booted. This time I decided to for some reason look at My Computer and that is when I discovered that my second hard drive went missing. It was also missing when I checked in 'device manager' & BIOS.
I haven't did a system resore yet but ironically when I was just about to do a system restore to an earlier point, the system restore put up a message that said "Changes made to drive G after this point cannot be reversed because the drive was either excluded from System Restore monitoring or was turned off or removed" The "G" drive is the 60GB slave drive that disappeared. Is my backup drive a lost cause? What can I do?

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic