How to Preserve a Slide Master in Microsoft PowerPoint
See Microsoft PowerPoint: Tips and Tricks for similar articles.
PowerPoint may delete slide masters that are not in use. Preserving a slide master ensures that PowerPoint will not delete it. You can preserve a slide master in just a few easy steps.
This feature works the same in all modern versions of Microsoft PowerPoint: 2010, 2013, and 2016.
- On the View tab, in the Master Views group (Presentation Views in PowerPoint 2007), click Slide Master.

- On the Slide Master tab, ensure the slide master is selected, then in the Edit Master group, click Preserve.

- A pushpin icon next to the master slide in the Slides pane indicates it has been preserved (this icon does not display in PowerPoint 2007).

