Right click on the first picture in the folder that you want to use in the slideshow. Select Open with -> Windows Photo Viewer. As soon as the photo viewer opens, click on the blue dot with the square inside of it to start the full screen slideshow. Once the slideshow has gone full screen, right click to control speed controls. Medium speed is 5 seconds per slide and slow speed is 10 seconds per slide. You can also set it to loop or shuffle via the right click option while within the slideshow. Unfortunately this built-in windows photo viewer can only do 10 seconds max... If you want to set the time for each image independently, you are most probably limited to using Powerpoint to set up each interval separately.
I checked both IrfanView and XNView right now and they cannot let you set a time for each IMAGE. The period is valid for all of them. Say 30 seconds for slide advancement.
You can't set a different time for each image. That sets a similar time for all images. Every x seconds, change to the next one. Either selected randomly in that folder, or automatic, sorted by date/file name/whatever.
I do not know of any software that would let you set 6 seconds for image A, 10 seconds for image B, 3 seconds for image C, etc....