DBAN is mainly designed to be ran all on its own to ensure that there's no interference from anything else from my experience.
Here, there be dragons! The following is very destructive if you don't know what you're doing. Proceed at your own risk.
If you don't have another computer to run DBAN on, then what you probably want is Eraser to wipe your hard drive. Eraser is a Windows program that can do several forms of wiping for you, (quick and fast to DOD clearance grade and more). You'll need to format the drive as something Windows can understand, like you've done with the shared drive. Then have Eraser wipe the disk. Be careful though, shredding is a one-way trip that is not usually recoverable in a cheap or easy manner. You can find Eraser here.