NirSoft PstPassword

NirSoft PstPassword can recover the passwords of Outlook PST files. You don't have to install MS-Outlook in order to use this utility.

After you run PstPassword, its main window displays the list of all PST files of the current logged on user (Under Documents and Settings\User Name\Local Settings\Application Data\Microsoft\Outlook). For each password-protected PST file, PstPassword provide 3 alternative passwords that will open the PST file.