This is a quick and easy tech-recipe for making changes to a PowerPoint show (pps) when your system does not launch PowerPoint but will run the slideshow.
1. Be sure to have your view so that you can see all extension types. (In Windows Explorer, go to Tools > Folder Options > View and uncheck the Hide extensions for known file types option.)
2. Rename the files with a .ppt extension. (i.e., meetingshow.pps -> meetingshow.ppt)
3. Now, you can make changes and edits to the show. You can also do the reverse, make a ppt into a pps just by changing the extension.