I suggest you the best tool to recover lost 7z file password without damaging saved data by the use of eSoftTools 7z password recovery software in sometimes by following these steps:-
  • Download and install this software in your system.
  • Browse the file which has to be open.
  • Select the recovery process from given three- mask attack, brute force attack and dictionary atack.
  • Click to proceed button and wait for sometimes.
More info:- 7 zip password recovery