Drive Cleanser ineffective

I downloaded and installed the demo version of Drive Cleanser. I want to completely wipe my hard drive and then reinstall windows. I've followed the instructions precisely, and I get the messg that files have been successfully wiped, but in reality nothing has changed: 1) all the programs are still there, 2) the disk viewer shows all the entries still there, and 3) scanning with a recovery program shows even more files.
My hard drive is currently formatted with 2 partitions - 1 sm FAT; 1 NTFS.

Can anyone help?

thanks-
Kathleen