Recovering a Lost Password
If you can't log on to a computer because you don't know the password, you're not alone. Forgetting passwords is one of the most common problems users face, especially if they've gone to the trouble of creating strong ones. If the computer is yours, finding that password is called "recovering a lost password." If the computer is not yours, the process is called "cracking." Either way, the tools and procedures are much the same. If you find yourself in this situation, you might need to explore the murky underworld of hackers to find the tools and techniques you need.

Traditionally, the best and fastest solution is for an administrator to log on to the computer and reset your password using any of the available account-management tools. This continues to be a viable solution for Windows 2000, but it comes with a huge caveat in Windows XP: If an administrator changes or removes another user's password, that user loses all personal certificates and stored passwords for Web sites and network resources. Without the personal certificates, the user has no access to his or her encrypted files or to e-mail messages encrypted with the user's private key. Windows XP deletes the certificates and passwords to prevent the administrator who makes the password change from gaining access to them.

Troubleshooting
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You can't access your encrypted files because an administrator changed your password.

When an administrator removes or changes the password for your local account on a computer running Windows XP, you no longer have access to your encrypted files and e-mail messages. That's because your master key, which unlocks your personal encryption certificate (which, in turn, unlocks your encrypted files), is encrypted with a hash of your password. When the password changes, the master key is no longer accessible. To regain access to the master key (and, by extension, your encrypted files and e-mail messages), change your password back to your old password. Alternatively, use your Password Reset Disk (see the next section) to change your password.

When you change your own password (through User Accounts or with your Password Reset Disk), Windows uses your old password to decrypt the master key and then re-encrypts it with the new password, so your encrypted files and e-mail messages remain accessible.

Microsoft Knowledge Base article Q290260 provides more information about recovering from this situation.

Libellés : Lost, Password, Recovering