To lock a PowerPoint presentation from editing, you can use the 'Mark as Final' feature. Here's how:Open the PowerPoint presentation that you want to lock.Click the 'File' tab in the ribbon.Click 'Info' in the left sidebar.Click the 'Protect Presentation' button, and then select 'Mark as Final' from the dropdown menu.Click 'OK' in the pop-up window to confirm.When a presentation is marked as final, users will be able to view it, but they will not be able to make any changes to the content. A message will be displayed at the top of the presentation warning users that the document is final and should not be edited.Note: If you need to make changes to the presentation after it has been marked as final, you can click the 'Edit Anyway' button in the warning message to edit the document. However, this will remove the 'Mark as Final' protection, and the document will no longer be marked as final.