If you had forgotten Windows Vista Password you can then use the password reset disk to reset your Vista password. However if you had lost your Vista password reset disk then its difficult to login to your computer. But there are some freeware tools like Ophcrack to crack your Vista password. Ophcrack is a freeware Windows password cracker based on the rainbow tables(Rainbow table is a lookup table which offers a time-memory tradeoff and can be used in recovering a text password from a password hash generated by a hash function). It comes with a Graphical User Interface as well as a text mode and runs on multiple platforms.

You can download the Live CD of Ophcrack from the website and burn the ISO image of Ophcrack on to a CD. Just boot your computer using the Live CD and you will be shown an option either to select the GUI mode or text mode. In some cases there might be problems with the GUI mode; then you can use the text mode. Ophcrack will then show you the list of all the users present in your computer and will try to crack the passwords for you. You will need to download the Vista Rainbow tables before that. The time it takes depends on the speed of your computer.

Features of Ophcrack

• Ophcrack Runs on Windows Vista, XP, Linux/Unix, Mac OS X
• Cracks LM and NTLM hashes.
• You can use Brute-force module for simple passwords.
• LiveCD is available to simplify the cracking.
• Loads hashes from encrypted SAM recovered from a Windows partition including Vista
• Free and open source software (GPL license).

You can download the Vista Rainbow tables here - “Download Vista Rainbow tables”