It may be a BIOS limitation, that stops the BIOS recognizing a large hard drive.
I assume you have the BIOS set to boot from a floppy first, so if you pop in a Win 98 or ME start-up disc, what happens. Do you boot to a command prompt then?
If so, look at the manufacturer of the drive, and download their "layering" software, that will fool the BIOS into believing the drive is smaller. You will loose any information that is already on the drive though.