If you switched to Windows 11 Enterprise IoT LTSC 2024 for the performance gains and lack of bloatware, you've likely hit one snag: images open in Paint by default.

Because LTSC removes the Microsoft Store, you can't easily install the modern "Photos" app. Fortunately, the code for the beloved, lightning-fast Classic Windows Photo Viewer is still inside Windows, it's just turned off. Here is how to turn it back on.

Step 1: Create the Registry Script

We will use a registry script to map the image file types (.jpg, .png, etc.) back to the classic photoviewer.dll.

1. Open Notepad.
2. Copy the code block below exactly as it appears.

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows Photo Viewer\Capabilities\FileAssociations]
".bmp"="PhotoViewer.FileAssoc.Tiff"
".gif"="PhotoViewer.FileAssoc.Tiff"
".jpg"="PhotoViewer.FileAssoc.Tiff"
".jpeg"="PhotoViewer.FileAssoc.Tiff"
".png"="PhotoViewer.FileAssoc.Tiff"
".tif"="PhotoViewer.FileAssoc.Tiff"
".tiff"="PhotoViewer.FileAssoc.Tiff"

3. Click File > Save As.
4. Name the file FixPhotoViewer.reg.
5. Crucial: Change "Save as type" to All Files (*.*).
6. Save it to your Desktop.

Step 2: Activate the Fix

Double-click the FixPhotoViewer.reg file you just created. Windows will ask for permission to modify the registry. Click Yes, and then OK when confirmed.

Step 3: Set Default App

Now that the viewer is unlocked, you must tell Windows to use it.

• Right-click any image file (e.g., a photo on your desktop).
• Select Open With > Choose Another App.
• Select Windows Photo Viewer from the list.
• Check the box: "Always use this app to open files".