What tool is the best or most reliable for resetting my seagate 20gb harddrive model number:- ST320014A? Any ideas?

Try DBAN, a bootable system that will zero out your drive automatically.

Do you want to securely erase the contents of the drive before replacing your computer, of simply zero it out before reinstalling?

If the former, dban is great. For the latter, you can use dban or use the "dd" program. Just be sure you don't zero out the wrong drive which ever you use.

I use SeaTools for DOS by Seagate, for zeroing drives:

http://www.seagate.com/www/en-us/sup...oads/seatools/

The bootable CD also had diagnostics, and will mark any bad sectors found.
Zeroing a 320GB HD took me about 2+ hours.

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bunjusnus:

If you have a linux system running mount that ST320014A device, and make sure you correctly identify it, check first by this: $ fdisk -l then write down the device name.

Then issue this command:

dd if=/dev/null of=/dev/<your-st320014a-deviceID> count=3 <Enter>

Example:
dd if=/dev/null of=/dev/sdc count=3
(this will write zeros to the entire disk 3 times. you need to wait. you may repeat this if so desired)

The tools recommended above are good as well. It is a matter of taste.

Hope this helps.