I can select the folder but the preview window still shows nothing, however, I did get it going. Seems that the slideshow browser is looking for slideshow files not pictures (I think as I don't know how to save a slideshow).
If I select picture from the slideshow folder it shows it, then if I select slideshow it works. I would purchase a book but I am amazed at the difference in the various versions of Windows 10. I tried a few things like trying to stop the screen from going to sleep and getting the screensaver to work but the various versions didn't match mine!!

I am running Windows 10 Pro 64bit and I actually purchased a genuine key!!

I still hate it though!!