How to format harddisk win2000

You cannot format the hard disk from within Windows.
You will have to boot into DOS or the Command prompt first.

To do this when your computer starts booting up, press F8 key across the top of your keyboard. This will give you a menu to choose from for starting your computer.

Start with "Command Prompt", then when it finally boots up, type "Fdisk".
This will let you re-configure your hard drive, and when you reload your OS (Windows) it will ask you to format it.

You may need a boot floppy. You can obtain one at bootdisk.com