My son has used "Eraser" to erase the contents of his 1 off IDE & 1 off SCSI drives.
He has re-partioned & re-formatted the IDE HDD and re-installed Windows 98 on it.
Windows is working, he can see the SCSI drive in Device Manager, but not in Windows Explorer.
He was trying to use "fdisk" to re-partition the SCSI drive, but was becoming confused and didn't proceed.
I don't have a SCSI HDD and don't know how it's done.

Can anyone lay out the proceedure?

Job done! :D

He used a program named "Easy SCSI Delux" to do it.