uploading powerpoint files from a computer without powerpoint installed

Hi, I do the building of the Presenter files for my church, from my Mac. I don't have powerpoint installed, but am often provided ppt files from preachers. I am unable to load these, which is such a nuisance! Presenter should be able to load files even though I don't run the software.

Note: We run Presenter from a different computer on Sunday mornings (we have a PC), which does have ppt installed. So, for now I am having to load those ppt files on that computer. Cumbersome having to use two computers for loading!

I could also do this with Keynote as well

I prep at home from a PC but then I often get Keynote presentations as most leadership team have Mac's, we do have a Mac at church but often I prep the service before Sunday