If you are a Windows System Administrator, IT Support or Windows power user, sometimes you may have a hard time to recover lost passwords from Windows machines. For these cases, Ophcrack is a really time saver software utility for you. Ophcrack use the rainbow tables to crack the passwords.
It is a GUI tool. That means, it is a very convenience tool for the people whose don't want to use or not familiar with command line programs.
The followings are some cool features of the Ophcrack software (copied form their site).
Currently, this time of writing, the latest version of Ophcrack is 3.4.0 and we can download as two version. First one is Ophcrack for all Windows platform, supporting Windows 2000, XP, Vista and Windows 7. It is a 32-bit installer. We need to install the software to use it.
The second one is Live CD version. With LiveCD, we don't have to install into the machine. We can burn the ISO files to the CD and run directly without installing. This is very useful if we don't know the Windows passwords. There are three versions available for the Live CD.