Ophcrack live cd is by far the best windows password recovering/cracking tool out there, because of its simplicity and how fast it cracks relative complex passwords, it cracked my 11 character password in less than 3 minutes, and if you are a Network Administrator or computer users in general, you could absolutely appreciate the usefulness of this tool. The tool is open source and free to download and use (at your own risk )… the technology it uses for breaking the windows password is “Rainbow Tables” and is a Time-Memory trade off. An easy way of describing this would be that Tables of possible Hashes are precomputed so that you can iteratively compare the windows hashes to precomputed bits and piece together the hash and its value more quickly than brute-force guessing. Well in this article we will go over the process of cracking a Windows XP password. (The process is the same for Vista except you would download the Vista live cd).
1- First download the version of live cd that match your OS. There are two version one for XP and another for Vista, it can be download from here . And burn the iso to a cd.
2- Insert your cd and make sure to select the correct boot order in the BIOS, and boot you PC.
3- Press enter, boot up and let the cd works its magic. It will automount your hard drive and detect the location of your windows passwords.
4- Here you can see Ophcrack has already cracked (7 character) password under 30 seconds.
5- And finally got the second password under 1 minutes and 30 seconds.
6- Restart the system, and use your password
by Jorge L. Vazquez