Need help with DBAN

Hi. I have a 150gb hard drive which I partitioned into a 50gb c: and a 100gb d:. 
 
Windows vista (which is installed on c:) would'nt let me create such a large partition without formatting. I overcame this using a Linux CD which forcibly partitions your HD and then installs Linux into the partition. I then cancelled Linux installation after the partition was created.

I have since filled d: almost to capacity with some "highly important data". (LOL)

I now want to securely erase c: using Darik's Boot and Nuke, but the only options are to erase ALL drives.
Is there a way for DBAN to erase c: but not d:, or will I have to buy a backup HD?

Use the Knoppix live CD. There's a program in there somewhere. QTParted I think.

>>2

Um, I did'nt understand your answer, QTParted seems to be a partition creator. As I said ITT, I have already partitioned my HD and now i want to securely delete 1 partition, whilst keeping the other.

Yeah, GPartEd can do that.
The GPartEd Live CD's pretty awesome, actually.
Haven't tried the Knoppix one, mind.

Yeah, GPartEd can do that.
The GPartEd Live CD's pretty awesome, actually.
Haven't tried the Knoppix one, mind.

Gparted is your best for partitioning. Get the live CD.

DBAN is to erase complete hard drives, it won't let you do just a partition.

Boot into a startup disk, whether it be a DOS disk or the recovery console. The us fdisk to remove the partition or as Anonymous said, use a live cd(like Knoppix) and remove the partion, for instance using the command cfdisk.