The Message Queuing Down Level Clients service provides Active Directory access for Windows NT 4.0, Windows 95, Windows 98, Windows Millennium Edition, and Windows 2000 clients that use the Message Queuing service on domain controllers. The Message Queuing service optionally uses information that is published in Active Directory to obtain routing information for security-related objects, such as destination public keys, and to learn about public queues. If you install Message Queuing in workgroup mode, Active Directory is never accessed. This service is only required on Windows Server domain controllers that run the Message Queuing service. Fix: (1) GPO: Computer Configuration\Windows Settings\Security Settings\System Services!Message Queuing Down Level Clients (2) REG: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\mqds!Start