Short answer:
Never use Ontrack. Period.

Do not use it for the same reason why people do not use FWB for Mac.

Because it has a proprietary format that is not recognized by anything else than itself.

Saying things like "do not use Ontrack ever" is not helping anything. Ontrack has it's uses, but of course you should be aware of the fact that you cannot read from a "Ontrack helped" drive in another machine that boots from another device. Ontrack is a good solution to BIOS HDD size limits, but should be used with its shortcomings in mind. They are only "readable" when you boot from them, in practice.

The thing here is though, I never seen a Pentium board that can not support 8GB disks. Are you sure you need to use Ontrack for your system?

So, to make a long story even longer... i have this Digital Venturis 575 (pentium 75) i'm trying to get running. The BIOS does not accept more than ~6300 cylinders, or about 3.2gb. So I set that size, booted off a w98SE boot disk and fdisk/formatted it. once i verified it could boot off the 3.2gb volume, i popped the CF card into my windows 10 machine and partitioned out the rest of the space. So after booting it back up in the Pentium machine, it boots off the 3.2gb C drive, and can see the ~4.5gb D drive. now i can get on with my life!