If your Windows Photo Viewer is not working or removed from your system, you can restore it easily with the help of a small, simple and easy tool Winaero Tweaker
After you download and Install Winaero Tweaker, run the application.
Find ‘Get Classic Apps’ on the left pane.
Click on the ‘Activate Windows Photo Viewer‘.
Now you should be able to get back ‘Windows Photo Viewer’