Free How to open PPS files
In case you want to open PPS files without installing the full copy of Microsoft Powerpoint, then you can definitely use the Microsoft Powerpoint Viewer, notice the “viewer” word at the end.
The Viewer version is free, so you don’t need to pay for use only PPS files. And do not trust to any site that request you to send SMS or pay any fee for the Viewer version.
To open these PPS files, just need to download the free version of Microsoft Powerpoint Viewer, from here (Microsoft website).
Then, you need to follow the installation steps and finally by doing doble-click on your pps file you can open it.