Geht ganz einfach: Öffne "Extras", dann "Fehlerkonsole", kopiere in das Feld "Code" folgenden Code hinein: openDialog("chrome://pippki/content/resetpassword.xul")
Klicke danach auf "Evaluieren".
Das Programm frägt nun nach, ob tatsächlich das Master-Passwort zurückgesetzt werden soll, klicke auf "Ja", wenn du vorher deine Mailpasswörter notiert hast - diese werden nämlich dann auch gelöscht...
Nun ist das Masterpasswort gelöscht und du musst deine Mailpasswörter neu eintragen.
Original-Anleitung von http://kb.mozillazine.org/Master_password:
Resetting the master password
If you have lost or forgotten your master password or you want to disable the feature, you can reset the master password. Resetting the master password will remove all stored password information. Upon resetting, you will lose all the stored information in the Password Manager, as this is a built-in security feature to prevent people from simply resetting your Master Password to gain access to your passwords.
For Firefox, you can also look at the Troubleshooting section of the Password Manager article.
* Firefox: Enter chrome://pippki/content/resetpassword.xul into the Location Bar (address bar), press the "Enter" key and click "Reset".
* Thunderbird 1.5: "Tools -> Options -> Advanced -> Saved Passwords -> Master Password -> Reset Password".
* Thunderbird 2 and above: Choose Tools – Error Console, paste the expression: openDialog("chrome://pippki/content/resetpassword.xul") and press the Evaluate button. That will open a dialog asking you if you want to reset your password.
* Mozilla Suite/SeaMonkey: "Edit -> Preferences -> Privacy & Security -> Master Passwords -> Reset Password".
Note: Upon initial installation, Firefox sometimes believes it has a master password in effect and the user is unable to change or remove it because the set master password is unknown to the user [2]. This situation sometimes occurs when a Mozilla Suite/SeaMonkey profile's passwords are imported into Firefox at install time. If this happens, reset the master password as explained above.
If resetting the Master Password via the chrome url didn't work then you need to remove the files that store the encryption key (key3.db) and the saved names and passwords (signons.sqlite and possible leftover files signons#.txt from previous Firefox versions).
See Password_Manager#Troubleshooting
Edit: Ich habe diesen Beitrag aus einem uralten Thread abgetrennt und einen neuen Thread damit eröffnet. Mod. graba