First:
Hard drives can fail and do so at the most unsuitable moments (this is knows as "Murphy's Law"). A hard drive is NOT suitable as the only (backup) storage of information. The real disaster might be that you don't have a decent backup, which (more or less) can be considered your own fault. Having to buy a new hard disk can't be considered a disaster, financially spoken.
Then:
The BIOS and DOS/Windows check for different things, so it's perfectly possible for the CMOS to 'see' the disk and for DOS and Windows not to do so. The BIOS communicates with the electronics of the drive, DOS and Windows look at the information on the magnetic platters. So the master boot record (MBR) and the partition table should be OK, the partitions should exist and they should be formatted Fat32 (with Windows 98), the drive should be able to rotate, and the platter-side electronics should be working correctly.
To do:
Mount the WD as slave and set the switches accordingly. Check that the BIOS recognises it.
Then boot into Windows, go to the command prompt and type fdisk /status (followed by enter). This would show the partitions on the drives, where they are and how they are formatted. Booting into real-mode MS-DOS is possible also.
Most likely outcomes of this experiment: drive is unreadable, no partitions exist or they aren't formatted FAT32. No doubt everythng used to be OK, but at the moment it isn't any more. As I said: this can happen (the MTBF might be 10 or 20 years, but note the M!).
A specialised data recovery firm might be able to get your valuable information back, if you pay them enough (which is more than you like).
Post again if you feel the need.
Good luck,
Kees
I have a 200 mghz Pentium with 64 meg ram. Before disaster struck I was running Win 98 with two hard drives in it, a 4 gig Quantum Bigfoot as master and a 20 gig Western Digital as slave. Both drives were partioned for a total of 7 partitions. The Quantum was partitioned into 3 partitions. The Western Digital was partitioned into four, 5 gig, drives. One day it wouldn't boot into Windows but at the c: prompt I could list all the files on both drives in all 7 partitions.
But things got progressively worse. Even though both drives are recognized in the CMOS when they are installed, now I can only access the files on the Quantum. Currently I have installed Windows 98 on a 1 gig Maxtor as as master. When the Quantum is added as a slave it is accessible by Windows and dos. When the Western Digital is added as a slave, although it is shown as present in CMOS, Windows and DOS do not recognize it. My most important files were saved on the Western Digital. I need help.

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