Windows – Reusing a USB flash drive with a hidden partition

I have a USB flash drive with a hidden encrypted partition on it. I'd like to reuse it, but so far I have been unsuccessful in wiping it.

It is an SanDisk Cruzer 8GB with what I assume was with the U3 software that originally came along with it.

Viewing it in Windows 7's Disk Management tool only reveals a 64MB RAW partition that I can't delete or format.

I attempted to use the diskpart command line tool, but was unable to format or delete the partition. Since I'm unfamiliar with the tool, I just might not be using the correct sequence of commands:

list disk
select disk 1
list partition
select partiton=1
delete partition override

(The USB flash drive is listed as disk 1, and within it, lists the 64MB partition as partition 1 with no other partitions.)

This sequence results in the error message:"There are no partitions selected. Please select a partition and try again."

What would be the correct way to wipe and reuse this USB flash drive?