If you have files with a PPS (PowerPoint presentations), but do not have it installed, do not worry, Microsoft provides a free reader files called PPS PowerPoint Viewer.
This program functions very well for files created with PPS:
Here's the link to letting you download this program:
Download PowerPoint Viewer
The article How to open PPS, PPT and POT without having installed the powerpoint ends here. You can find more related information in the following links: