Now go to the Tools menu and then select the Protect option. · Next, create a password for your PDF and also enter a password in the preferences ‑ Adobe Flash Player preferences. Once you are in the password settings click on Lock. How to lock Adobe Acrobat files from being edited, copied, shared or printer-protected? Mar 31, 2022 — Click the protect” link, then select enable security methods.” How to protect the Flash Player from being edited? Click protect” in the menu. The Secure PDF screen How to lock Adobe Acrobat files from being edited and copied? Click the protect button, then enter a password for your Adobe Acrobat PDF. Click OK” to save your password. Security and PDF Security You can't edit or change the security of your PDF files unless you first enable and use one of the security options described earlier. These are the Security settings that you can select, and any other settings that you have made to them.