You can change the background of your PowerPoint slides using the "Format Background" feature located in the "Design" tab.

Microsoft PowerPoint is used worldwide for meetings, presentations, and education. Here's what to know about the program and how to get started.

On the main menu, select the template titled Crimson Landscape Design slides. The background on this slide is an image. The easiest way to customize it is to select a different image.

Launch Microsoft PowerPoint, and open the PPTX file for which you want to use a GIF as the background. Select the appropriate slide. Click the "Design" tab, and locate the "Background" section.