Specially, it 'tells' the app that it can handle the following file types: The Registry file re-creates the missing 'capabilities' for the Photo Viewer.

It allows you to restore Windows 11 defaults and undone the Photo Viewer app registration in the OS. Also, the ZIP archive includes an undo tweak, Disable Classic Photo Viewer.reg. The Registry file restores the system registration and enables the Windows Photo Viewer app. Once you add the contents of the REG to the Registry, you need to set file associations to Windows Photo Viewer.Double-click the Enable Classic Photo Viewer.reg file and confirm the merge operation.Extract the included REG files to any folder.Download these Registry files in a ZIP archive.Enable the Classic Windows Photo Viewer app Optionally, you can add the Preview context menu item that invokes the classic Photoviewer app. Second, you need to associate the image files with Windows Photo Viewer and set it as the default app for them.

First of all, you need to activate the app in the Registry. To enable the classic Windows Photo Viewer app in Windows 11, you need to perform a number of steps. Add Image Preview context menu for Photo Viewer in Windows 11 Enable Windows Photo Viewer in Windows 11

Microsoft photo viewer