I think OP’s question was pretty clear.
UE defaults to whatever photo editor is set in the Window’s registry. So, changing the editor is done in the Windows registry.
Steps:
- Press Windows key + R
- Enter ‘regedit’
- Press ctrl + F
- Check the “keys” box. Disable the ‘Values’ and ‘Data’ box.
- Search ‘SystemFileAssociations’
- The ‘SystemFileAssociations’ folder will be selected. Double click to expand.
- Scroll down to the folder named “image” and expand.
- Expand the shell > edit folders and select ‘command’
- In the right side panel double click “(Default)” under the “Name” column
- Paste the file path to the image editor you want to use. Make sure it is in quotes. This must be followed by a space and then “%1” with quotes.