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A “Splash Screen” and an Application Icon in your Microsoft Database are stylish additions that result in a slick, professional-looking application. Your Application Icon will appear in the title bar of your Forms and Reports. I use the amazing GIMP for all my graphics needs. GIMP has the option to export to the Microsoft Icon format (.ico).
See also:
Implement
To add your icon to your database:

- Select File » Options
- Select the Current Database section
- Add an Application Title while you are at it!
- Click the Browse button
- Select the Use as Form and Report Icon option
- Click the OK button

- The dialogue window is already set to filter for Icon format files
- Use the Search box to search by extension
- Select your icon file
- Click the OK button
Restart
You must restart Access and re-open your database to see the result.
Drag on the image below to see the before (default logo) and after (custom icon) screenshots:

