This policy setting allows you to display a custom message to users in a notification when a device installation is attempted ...

This policy setting allows you to display a custom message to users in a notification 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 Detail Text box when a policy setting prevents device installation.

If you disable or do not configure this policy setting, Windows displays a default message when a policy setting prevents device installation.