I was wanting to say you could do this with Knoppix but couldn't remember what the binary was called. A quick google search turned up:

http://www.digitalissues.co.uk/html/os/misc/shred.html

Using Knoppix (free download/install: http://www.knoppix.org/
And the info from the above referenced page:
Shred
Shred is part of the GNU Core Utilities
I run shred under Knoppix 3.9
# shred -n 2 -z -v /dev/hdxy

-n 2 Overwrite the partition 2 times with random data
-z Finish with one pass writing of zeroes
-v Show it's progress

Change x to reflect the IDE drive number (ie /dev/hda)
Change y if needed for a particular partition (ie /dev/hda1)
Be careful !!
# shred -n 2 -z -v /dev/hda will shred all of the first IDE hard disk
# shred -n 2 -z -v /dev/hda1 will shred only the first primary partition of the first IDE hard disk
Not sure of the quality of the program, but it would do essentially what you want and that is to overwrite the disk with random data a few times to remove any easy chance of recovering data through forensic utilities and doesn't require that you have any other OS boot disk.

Also note, I did see a few articles about doing this with dd using different devices as input/output to essentially do the same thing (for example: Here


To me either of these is better than installing an OS which WILL NOT NECESSARILY destroy the data on the hdd and will also avoid any issues with filesystem types (like for example, if you tried to use fdisk from win98 on a Win2k/WinXP system with NTFS).