How to Break a Computer Passwordby Charles Poole
One of the worst things that a computer user can run into is forgetting their password. When you forget the password to your computer, you can't log in to your account or access the files on your system. You can break the password, though, using the Windows installation disc that came with your system.
Insert your Windows install disc into the optical drive on your system and turn the computer on.
Accept the license agreement when it appears on the screen.
Press the "R" button when you are asked if you would like to repair your system.
Wait for the install process to start. When the computer restarts, you will be prompted to "Press any key to continue." Don't press any key.
Watch the bottom of the screen for the "Installing Devices" prompt. Press the "Shift" key and "F10" keys together to bring up a command prompt.
Type "nusmgr.cpl" into the command prompt and press the "Enter" key on your keyboard to go into the User Accounts page.
Click on the "Administrator" account and then change the password in the fields. Click "OK" and then restart the system.