No matter what the situation, computers have always been designed to be able to format from the boot screen without the need of a password or login for the operating system or your BIOS. This was designed in case you lost your password or couldn't access the operating system, making it so you could refresh the system and get back into the computer.

Getting Started

In order to format the computer, make sure you have your original operating system and drivers discs. The operating system disc formats the computer while the driver disc restores the hardware settings so everything on the laptop works. If you udpated the operating system, the new disc will work just as well. Put the disc in and start the computer. It will give you the option to boot from the disc. Click "enter" to accept. A step-by-step guide will walk you through the steps of formatting the drive and re-installing the operating system. This process will take about an hour to finish. Once it has completed, the laptop will reset and boot into the new operating system. Insert the driver disc and allow it to reinstall the drivers back onto the computer.

BIOS Operation

Your BIOS settings are a whole new issue when it comes to computers. If you have set a BIOS password and need to bypass it, there are a select few ways to do this. Older computers have an extra backdoor password for technicians to be able to get in when trying to fix your computer; the resources have a list of passwords you can try, but if none work the only other step is to get third-party software. !BIOS is a freeware program, one of very few, that will blast your BIOS password for you. This must be done through the operating system so hopefully you have enough functionality to get into your operating system. Make note of your BIOS type and version that you are on and then start the process. Go to your Start tab and select "Run." Inside here, type "cmd" and click "OK" to get to your DOS prompt. In the DOS prompt, enter "cd desktop" to access your desktop in DOS. Type in "bios320.exe" to access your blaster. Using your arrows go down to "Crackers" and press your right arrow. Press "1" to enter system password and then "1" again which will retrieve and show you your BIOS password so you can fully format the computer.

Source:

Mahalo.com: Reformatting a Laptop