SlideShow function not working

Hello, this is my first post on your forum (and most likely the only one, as I usually do not use forums for more than lurking :/)
I have read alot of threads where people have had this problem, and I have tried most fixes but to no avail.
I have checked my power-saving settings, they are correct.
I have ran SFC and rebooted.
I have checked if any of my software is interfering, they are not.

The only thing I can say that seems to be wrong compared to a computer where this works, is that the theme preview image, where is supposed to show what images are in the slideshow / what image is in the theme is not updating. It is only black.
After making a theme with several images and right-clicking the desktop, I get the option to go to the next image in the slideshow. After clicking it, it gets removed from the right-click menu and the image is NOT changed.
I have tried using images from the user folder on my C: drive as well as from the library I keep on my D: drive, but it has had no effect.

Another strange thing I noticed is that if I try to change the background on a theme, it defaults to the "Solid Colors" location, and if I select on of the colors from the list, that gets set as the preview image even after I change to a new image from a different location.

If you have any suggestions, need me to specify something or need any information I did not mention here, lemme know.

Thanks man, it worked!
I hope others with the same issue finds this post as well