Hello Mike,
You can redo what you have done. You will need to back up any files you want.
Get a good copy of a boot disk, Eg: if you are using Win98 get a win98 floppy.
Reboot the computer with the boot disk in the dirve. We want to boot from the floppy. Then type " fdisk " enter . There you will see a few options( Im trying to tell you how from memorry its a bit hard not seeing it right now...) I am thinking that you should be able to add another partition with out removing the old one. Look for an option Creat partition,see where you can get with this. If you can;t add onto what you have you will need to delete the old partition.
Make a new partition if you have deleted the old one don't set it to full chose the size you want, Eg you wanted 6gig and 5 gig, the first will be about 6000mb, then make one more with the full option if you only want two drives. Then after you reboot you will need to format both of the drives(partitions) ... I hope this helps
Elf