Microsoft Message Queuing

Applies To: Windows 7

The Downlevel Client Support Service that is a part of Microsoft Message Queuing (MSMQ) is being removed from Windows® 7.

What are the major changes?

As a result of this change, Windows°NT®°4.0and Windows®°2000MSMQ clients running against Windows Server® 2008 R2 domain controllers that have no Windows Server®°2003 or Windows Server® 2008 domain controllers in the same environment will not support MSMQ in domain mode. This change affects customers who have Windows°NT®°4.0 or Windows®°2000 clients that are joined to domain controllers, which have been upgraded toWindows 7. If any domain controller in these environments is running Windows Server 2008or earlier, full functionality remains available.

Are there any dependencies?

MSMQ has several dependencies on a directory service infrastructure; in version 1.0 the MSMQ product implements its own directory through a SQL-based database named MQIS and subsequent versions of MSMQ use Active Directory as its directory. MSMQ 1 and MSMQ 2 (Windows®°2000) clients use a proprietary RPC-based interface to communicate with the underlying MSMQ Directory. The MSMQ directory service server implements the server-end of this RPC interface and is required to be installed on the domain controller. This proprietary RPC interface is deprecated in MSMQ 3 (Windows XP / Windows Server®°2003) in that, newer MSMQ clients use LDAP to directly communicate with the Active Directory. The deprecated RPC Server is still available in Windows Server®°2003 and Windows Server 2008domain controllers as a separate Down-level Client Support service to enable inter-operability with Windows®°2000 and Windows°NT®°4.0 clients.


There are two workarounds for this:

  • Upgrade the client from Windows°NT®°4.0 or Windows®°2000 to Windows°XP, Windows Vista®, or Windows 7.

  • Add a Windows Server®°2003 or Windows Server®°2008 domain controller to the environment.

Additional references

For more information on MSMQ inWindows Server® 2008 R2, see MSMQ Service in the Microsoft TechNet (