This policy setting allows you to prevent the installation of devices that are not specifically described by any other policy setting.If you enable this policy setting Windows is prevented from installing or updating the device driver for any device that is not described by either the "Allow installation of devices that match any of these device IDs" or the "Allow installation of devices for these device classes" policy setting.If you disable or do not configure this policy setting Windows is allowed to install or update the device driver for any device that is not described by the "Prevent installation of devices that match any of these device IDs" "Prevent installation of devices for these device classes" or "Prevent installation of removable devices" policy setting.
System\Device Installation\Device Installation Restrictions
Machine
At least Windows Vista
HKLM\Software\Policies\Microsoft\Windows\DeviceInstall\Restrictions!DenyUnspecified
DeviceInstallation.admx