If you noticed Microsoft has taken away the default Windows Photo Viewer in Windows 10. This can be quite annoying for it you want to just open one photo that isn’t meant to be stored in a photo library. I found this trick online and wanted to share it. If you have gone looking in your “Program Files” folder looking for this application you won’t find it. Technically this is a COM surrogate application and must be called using the Run DLL executable (rundll32.exe). If you need to script this COM application and would like to know the program location you can also run the following command:
%SystemRoot%\System32\rundll32.exe "%ProgramFiles%\Windows Photo Viewer\PhotoViewer.dll", ImageView_Fullscreen [Optional] [Path to Image File]
To add this feature back into Windows 10 you must add the following registry keys and then set this COM application to be the default photo viewer.