Ophcrack is an open source and free program that bypass Windows passwords by using LM hashes through rainbow tables. The Ophcrack Windows password reset is by far the fastest freeWindows 7 password hacker tool available. The program includes the ability to import the hashes from a variety of formats, including dumping directly from the SAM files of Windows. On most computers, ophcrack can crack most passwords within a few minutes .Rainbow tables for LM hashes of alphanumeric passwords are provided for free by the developers. By default, ophcrack is bundled with tables that allows it to crack passwords no longer than 14 characters using only alphanumeric characters. Available for free download are two Windows XP tables, one small and one fast, and one Windows Vista table . Objectif Sécurité has even larger tables for purchase, intended for professional use . Larger rainbow tables contain LM hashes of passwords with all printable characters, including symbols and spaces, and