When a password for opening is set, the document's content is encrypted and cannot be viewed without the correct password.
If you encounter the enter password dialog (see below) when opening the document in Microsoft PowerPoint, it means that the document is password-protected.
If an opening password is set, a strong encryption method is used, so the password generally cannot be recovered instantly. However, with Office Password Recovery's unique methods, in most cases passwords are recovered very quickly.
To set, modify or remove a known (or recovered) password for opening: