Make Presentation Read Only. When selected Always Open Read-Only tells readers the file is read-only and shouldnt be edited. Then Click Sharing Permissions options and click.

Heres how using OneDrive and OneDrive for work or school. This would make the PowerPoint Presentation as a read-only. Read on for more tips about giving an engaging presentation.
Select presentation File print select save as pdf This will create a pdf version of your keynote which is read only Hope this helps.
In the options on the drop-down menu click on Mark as Final. This would make the PowerPoint Presentation as a read-only. Open the document you want to protect and then click on File. The following warning message would also be displayed.