DISCLAIMER!!! - These links and/or programs are provided FREE for your benefit. While these programs have proven very useful to me and countless other people, your mileage may vary. Tim's Corner will not accept responsibility for damages of any kind related to these programs and their use! Read their documentation and if you choose to benefit from them, do so at your own risk.
Particularly be aware that the low-level format utilities will irreversibly format your hard drive (this is what they are designed for); also they will not format one partition alone, but will format the entire drive. I recommend extra caution when formatting with more than one drive in the machine until you know the program well enough. One could always disconnect the extra hard drives at first for an extra measure of safety. If you do not understand what I am saying about these utilities it would be safest to avoid them or ask a friend who knows.