If you're getting an “Application not found” error when trying to open folders on Windows (double-clicking a folder does nothing or shows an error), it's likely due to a broken folder association or registry issue.

I recently ran into this and finally resolved it using a simple registry fix. Here is how to fix.

Solution: Restore Folder Association via Registry

You can fix the issue by resetting folder open behavior in the Windows Registry.

 

1. Open Notepad.
2. Paste the following text:

3. Save the file as:
   fix_folders.reg
   (Make sure to choose “All Files” under "Save as type")
4. Right-click the file and choose Merge.