fdisk does not see the drive mounted

Most likely, your motherboard does not recognize the drive.

It may have a 2GB or an 8GB drive detection limit.

Start by entering BIOS setup, and verify that the drive is detected properly.

If not, your lowest cost option, is to use the drive manufactures setup software.
These normally include a 'drive / BIOS overlay' program that tricks the motherboard into recognizing the larger drive.

My personal choice, is to use a PCI IDE controller card. This not only takes care of the large drive issue, but allows you to use the higher data transfer rate of newer drives.

Note: If you plan to use W95 on this drive, be advised that most versions of W95 ONLY support 2GB partitions.

Chas