In XnView's case that should include the following options:
- General » Operations
- Display all image file types (f/k/a Use all formats available)
- Interface » Interface
- Language
- System integration » Integration
- Add 'Browse with XnView' to context menu
- Add XnView to 'Send to' context menu
- Associate Slide File with XnView
- Add XnView as applications for USB events (camera, scan, ...)
- Use XnView Shell Extension
- Add XnView's Icon to Desktop
- Add XnView to Programs Menu
- Add XnView to Start Menu
- Save options as INI in folder / in registry
- Folder used for other files