Resize Partitions or Reconfigure Disk?

I have a used NT4 SP6a workstation that I am setting up for a new user. The current disk configuration is:
C: 327MB FAT
D: 2674MB FAT

I am not done installing software to the D: drive, and am running out of room on the C: drive!! I understand that software is writing to the system folder, as required.

So, my question is, can I reconfigure this 3GB drive to be a single drive? Although I have installed software, I am willing to rebuild it.

I have tried installing a fresh copy of NT, but I didn’t see how I could change the existing partitions, or set it up as a single disk drive. Also tried using Disk Administrator to delete the partitions, but it wouldn’t allow me to delete the partition with the system on it.

Did I missed something, or are there other ways to resolve this?