This policy setting allows you to display a custom message title in the notification balloon when a device installation is ...

This policy setting allows you to display a custom message title in the notification balloon when a device installation is attempted and a policy setting prevents the installation.
      
If you enable this policy setting, Windows displays the text you type in the Main Text box as the title text of the notification balloon when a policy setting prevents device installation.

If you disable or do not configure this policy setting, Windows displays a default title in the notification balloon when a policy setting prevents device installation.