Knoppix is a Linux live-CD operating system that runs off a CD instead of being installed onto the computer's hard drive. Operating systems like Knoppix are perfect for situations where you need to perform some type of repair operation on your computer. For example, if you forgot a password for a user account on Windows, you can boot your computer into Knoppix through the live CD and reset the password with a tool on the Knoppix operating system.
Place your Knoppix Live CD into your computer's CD tray, restart the computer and wait for the computer to boot from the Live CD.
Press the "Enter" key at the Live CD menu to boot into Knoppix.
Open the Linux "System" menu, then click on the "System" and then "Applications" menu.
Click on "Security/Reset" in the program list, then select the Windows account that you want to reset the password for.
Click "Change Password," type in the new password and then click on the "OK" button.
Restart your computer and allow the Windows operating system to boot up, using your newly reset password to log in.