FDisk, FAT32, format - in DOS. Check name of drive in BIOS or device manager before FDisk. To be sure (to be sure) before you boot to DOS, unplug the ribbon cable to the original hard drive, that way you can't hurt it, but FDisk should identify the drive you are about to work on, and having done thejob in September I am sure (but can't remember how) that it is possible to Fdisk things other than the C drive.

When I added the extra drive in September (it has since died, possibly due to heat in the removable hard drive caddy which had no self ventilation) I was very vexed to find that in 98 it is NOT possible to designate the new drive: it will automatically become D, so you may have to adjust references to things that were partitions above C on your old drive. In XP you can designate the new drive, and again I have done just done it for a mate, designating the new drive F and G, but it can be done from Windows. Details I found in the knowledge base, and cannot remember. I am pretty sure XP was the first version of Windows to permit such designation.