If you ever forget your password for logging into your local computer then you are out of luck. Sometimes you can remember the backdoor administrator login account but most of the time you won’t be so fortunate. Well, thanks to ophcrack you can now discover all of the login accounts and passwords for that computer. It works with windows and linux systems.
You have two ways to use OPHcrack:
1. Create a bootable CD which requires no installation. Just download the ISO file and burn it to a blank CD and you will be good to go. Note: Make sure you change your system settings so that it boots from CD-ROM before your local drive. Usually pressing F2 or F12 at bootup gets you into your system settings.
Download Page for the ISO for XP and Linux or Vista. What? You don’t have a CD burning package? Then download ISOBurn, ISO Recorder or Create-Burn ISO. All three are free.
2. Install ophcrack while you are logged into a system and want to collect all of the login accounts and passwords before shutting down and possibly not be able to login again. Download the version you need here.
What you see is what you get
There’s a graphical windows interface and a plain command line text mode just in case your system has troubles with the GUI.
Here’s what the GUI looks like. 
Conclusion
I’ve used it a few times and it works like a charm!