Note:  Ophcrack is only intended for computer geek, not ordinary, nontechnical folk. For average computer users, the most efficient and easiest way is to use Reset Windows Password utility.

Ophcrack is a free (open source) Windows password cracker/recovery tool based on rainbow tables. It is a very efficient implementation of rainbow tables done by the inventors of the method. It comes with a Graphical User Interface and could be used to recover Windows 7/Vista/XP password.

How to Recover Windows 7 Password Using Ophcrack?

1. Download the Ophcrack from the official website. When you go to Ophcrack download page you will notice there are LiveCD ISO’s for Windows 7 and Windows XP. Based on the operating system of your locked computer download the ISO for that operating system (Windows 7 or XP). It won’t hurt to download both because you never know when you might need them.
2. Burn the ISO image on to a CD. It will create a bootable CD for you. I use BurnCDCC for this. You can use anything you like.
3. Now put the CD into the CD-ROM and make sure you set CD/DVD as the first boot device inside the computer BIOS.
4. When it boots from the CD, you will see the list of the accounts on the computer.
5. The machine will do its thing and just leave it. After a while, you will see password has been recovered and displayed on the screen beside the accounts those are not password-protected.
6. After you see it – remember it just reboot the machine and you should be able to log on to Windows 7 system.