Starting with Windows 10, when you open an image file, the image would no longer be viewed in the Windows Photo Viewer. Instead, you’ll be switched to the new Microsoft Photos, which is plagued with performance and reliability issues. If you upgraded from Windows 7 or 8, it’s easy to get the old Windows photo Viewer back as you only have to change the default apps. For Windows 10 users who performed a clean install of the operating system, we instead need to use a Registry hack to get it back as described below.
Source: https://www.bleepingcomputer.com/news/microsoft/how-to-restore-windows-photo-viewer-in-windows-10/