I recommend you use SysInspire 7z password recovery software for recovering 7z file passwords. This tool recovers mixed password, symbolic, and numerical passwords. It has 3 powerful techniques that can recover passwords. After recovery of your full password then you can copy it onto a clipboard. By using the Brute force attack, Mask attack, and Dictionary attack, you can smoothly unlock the 7z file password. It has a demo version that can allow users to recover the first 3 characters of the 7zip file password.
If you want to extract password-protected 7zip files, I suggest you download eSoftTools 7z password recovery software. This software contains 3 utilities that are helpful for users. This software helps users in getting multiple types of passwords. Mask Attack, Brute Force Attack, and Dictionary Attack. It supports all versions of Windows OS.