Can’t run FDISK…help?

I recently ran fdisk on my computer, and performed a fresh reinstall of Windows 98. I created an extended partition which included three logical drives. (It’s a 13 Gig drive.) I then decided to experiment with Win98/Win2000 dual booting. I ran FDISK and deleted the logical drives, then the extended partition. This left me with Win98 on the Primary partition (3 Gig.) I then proceeded to install Win2000 on the extended partition thinking that I could further partition later. Stupid mistake;I should have known better. I want to start over, but when I run FDISK, it won’t delete the extended partition because it sees logical drives. But when I try to delete the logical drives, there aren’t any defined. Can anyone shed some light on this for me?