You should try eSoftTools 7z Unlocker software to unlock the lost password of 7z file. It recovers all types of password combinations through 3 Advanced techniques such as Brute Force Attack,Dictionary Attack and Mask attack. It has many features and advantages to extract 7z file password. Like copy to clipboard-this tools store the recovery password copy in clipboard for future use. Users can download a free demo version to show the first 3 letters of the password.