Is there any data on the disk that's of value (or any other partitions)? If not I think the most expedient thing to do would be to wipe the drive using dban.
http://www.dban.org/ There's a floppy version of it too.
To speed things up, for method, pick fast wipe (so it does only one pass with zeroes), and for verify, pick none. Navigation is done via the arrow keys, and selection is done by using the space bar. Remember to select your drive before pressing F10 (you should have *** in the brackets by the drive set to wipe), otherwise it'll be done before it even starts!