Downloading the Windows 10 messed up photos in my photo gallery

I also installed Windows 10 yesterday and where my photos uses to show up right in the middle of the screen, they show up in the upper left hand corner of the screen with a small part of the picture hidden.  I have tried everything I can think of to remedy this but now after 2 hours I quit.  If anyone has the same problem or a solution, I would really appreciate a hand with this.  It looks like the pictures are being presented in an almost invisible black box that is almost the same size as the original pictures that were presented.