|1: Go into Safe Mode. Then on logon prompt, select Guest to access entry.|
2: Click on Start > Run, Copy & Paste > "control userpasswords2" without quotes & hit > Enter.
3: Click on the on the user account whose password is forgotten & click on Reset Password.
4: Enter the new password then click OK to exit. Reboot computer.
Obtain Windows CD (XP, Vista, 7, 8, doesn't matter process is largely the same)
Here is a sample using a Vista CD.
1: Set the bios to boot from CD first.
2: Boot off Windows CD into setup.
3: At setup hold shift key and press F10.
4: This will bring up a command window.
5: In the command window type "control userpasswords2" without quotes & hit Enter.
6: Highlight admin account and reset and set a new password.