You are unable to open a PowerPoint Show (.pps) file.
Neither PowerPoint nor PowerPoint viewer is installed on your computer.
Install PowerPoint or PowerPoint Viewer on your computer.
If you don't own PowerPoint, you can download and install the free PowerPoint Viewer to view full-featured presentations.
You may also be able to use PowerPoint Mobile or PowerPoint Online to view presentations without having PowerPoint installed. See View a presentation without PowerPoint for more information.