Prohibit adding items
User Configuration\AdministrativeTemplates\Desktop\Active Desktop
Prevents users from adding Web content to their Active Desktop.
This policy removes the New button from Web tab in Display in Control Panel. It also removes the New Desktop Item command from the Active Desktop menu. As a result, users cannot add Web pages or pictures from the Internet or an intranet to the desktop.
This policy does not remove existing Web content from their Active Desktop, or prevent users from removing existing Web content.