If you don’t want others to open and modify your PowerPoint presentation, you can lock the presentation. Here, this guide will introduce several ways to protect a presentation file from being copied, edited, and changed by unauthorized others.
If you want to let people know that a presentation shouldn't be changed, you can use the Mark as Final feature. When a presentation is marked as final, typing, editing, commands, and proofing marks are disabled or turned off and the presentation becomes read-only.
Step 1: Click the File tab to go to Backstage view.
Step 2: From the Info pane, click the Protect Presentation command.
Step 3: In the drop-down menu, choose the option that best suits your needs. select Mark as Final.
Step 4: A dialog box will appear prompting you to save, click OK.
Step 5: Another dialog box will appear, click OK.
When you mark a presentation as final, PowerPoint asks you to save the file. The next time you open it, you will see a yellow MARKED AS FINAL message at the top of the file. If you click Edit Anyway, the presentation will no longer be marked as final.
If you want to prevent people from editing it, you can use the Restrict Access option:
Step 1: Click on File tab to go to Backstage view.
Step 2: In Info tab, click Protect Document button. And then select Restrict Access option.
To protect PowerPoint 2010/2013/2016 presentation, use these steps as follows:
Step 1: Click on the File tab, choose Save As option. Select one location you will save this *.pptx file.
Step 2: In the Save As dialog, click the Tools button at the bottom and then select General Options.
Step 3: Type a password in the Password to modify box and click OK. Reenter the password to modify and click OK to confirm. When you return back to the Save As dialog, click Save to save this presentation.
Then the password to modify will lock this PowerPoint 2016 presentation and prevent it from being edited or modified. Keep your password in a safe place. If you lose or forget the password, Microsoft won’t help recover it and you have to remove the password with a third-party utility like PowerPoint Protection Refixer.