And after you do that, you can set it as your default photo app.
Windows 10 uses the new Photos app as your default image viewer, but many people still prefer the old Windows Photo Viewer.
You can get Photo Viewer back in Windows 10, though. RELATED: If you upgrade a PC running Windows 7 or 8.1 to Windows 10, Windows Photo Viewer will be available and you can set it as your default photo viewer if you want.
: A big thanks to nexus over at Ten Forums for locating the required registry settings. If you don’t see it at first, scroll to the bottom of what’s listed and click the “More apps” option—it’ll show up.
And remember—this step is only necessary if you’re using a fresh Windows 10 system. Select the “Always use this app to open .___ files” option, and then click “OK.” Windows Photo Viewer will now be the default image viewer for that type of image file.
You’ll only have to do this the first time you open each new type of image file.
This is a pain since Photos is the default picture viewer in Windows.
If your app still doesn’t work after the reset, you can try a full resintall of Photos.
Unfortunately, Windows doesn’t let you uninstall Photos normally, so you’ll have to either remove it via Power Shell or using a third-party uninstaller. Once you’ve done this, re-download Photos from the Store and see if it’s fixed.
Windows Photo Viewer is a default program to view photos in Windows 7, Windows 8, and Windows 10. You can use Adobe Photoshop, Irfan View, Photo Retouch, Raw Image Viewer etc.
However, there are several cases reported about Windows Photo Viewer not able to open CR2, NEF and other image file formats, along with this error message. When an image file format is not supported by Windows Photo Viewer, you can convert the file to JPEG, TIFF, or PNG which can be viewed in Windows Photo Viewer.
RELATED: You also can’t simply point image files at a specific file to associate them with Photo Viewer, either.