The information below will help you to setup a Raspberry Pi with Raspbian OS that will play a slideshow/PowerPoint presentation using a PPT/PPTX or ODP file.
The system will be setup to automatically login to a desktop, load Libre Office Impress (PowerPoint alternative) and run a slide show presentation with custom slide show settings defined.
Please note, MS Powerpoint slideshows might not display 100% correctly in Libre, you can save from MS PP to an open format or to ensure an output as expected, just grab Libre office for PC or Mac, it is Free after all!!
Instead of using a costly full blown MS Windows desktop PC we can use a Raspberry Pi that not only costs hundreds of pounds less to buy but also consumes a minor percentage of power that a full desktop uses as well as being small enough to attach to the rear of the display device.