Graphics update freezes on a Windows Server 2012-based RD Session Host server that is under a heavy load

Applies to: Windows Server 2012 DatacenterWindows Server 2012 DatacenterWindows Server 2012 Essentials


Consider the following scenario:
  • You have a Remote Desktop Session Host (RD Session Host) server that is running Windows Server 2012.
  • The RD Session Host server has more than 50 Remote Desktop Services (RDS) clients connected, and that causes the RD Session Host server to be under a heavy load. 
  • The RD Session Host server receives a Remote Desktop Protocol (RDP) session from a Windows 7 Service Pack 1 (SP1)-based RDS client that has RDP 8.0 installed.  

    Note For more information about how to install and enable RDP 8.0 on a computer that is running Windows 7 SP1, click the following article number to view the article in the Microsoft Knowledge Base:
    2592687 Description of the Remote Desktop Protocol 8.0 update for Windows 7 SP1 and Windows Server 2008 R2 SP1
In this scenario, the graphics update for all the connected clients freezes for at least 100 milliseconds. Additionally, this issue recurs when the RD Session Host server receives new RDP sessions from any other clients.


This issue occurs because a User Datagram Protocol (UDP) connection object is not created immediately after an Acknowledgement (ACK) packet is received. This behavior provides an opportunity for all the other connections that have a pending data to be sent. Additionally, when multiple connections are established at the same time, if the higher layers of some connections are not ready, a 100-millisecond delay occurs to let the higher layer be registered with the RDP-UDP layer.


Hotfix information

A supported hotfix is available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing this specific problem.

If the hotfix is available for download, there is a "Hotfix Download Available" section at the top of this Knowledge Base article. If this section does not appear, submit a request to Microsoft Customer Service and Support to obtain the hotfix.

Note If additional issues occur or if any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. For a complete list of Microsoft Customer Service and Support telephone numbers or to create a separate service request, visit the following Microsoft website: Note The "Hotfix Download Available" form displays the languages for which the hotfix is available. If you do not see your language, it is because a hotfix is not available for that language.


To apply this hotfix, you must be running Windows Server 2012.

Registry information

To use the hotfix in this package, you do not have to make any changes to the registry.

Restart requirement

You must restart the computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace a previously released hotfix.


Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

More Information

For more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base:
824684 Description of the standard terminology that is used to describe Microsoft software updates

Additional file information

Additional file information for Windows Server 2012

Additional files for all supported x64-based versions of Windows Server 2012
File nameAmd64_4588ac68671158526912e337025e7bcc_31bf3856ad364e35_6.2.9200.20590_none_e4b63aab67a3b131.manifest
File versionNot applicable
File size729
Date (UTC)21-Dec-2012
Time (UTC)21:32
PlatformNot applicable
File nameAmd64_microsoft-windows-r..s-regkeys-component_31bf3856ad364e35_6.2.9200.20590_none_88d29fa5aabcb60e.manifest
File versionNot applicable
File size13,555
Date (UTC)21-Dec-2012
Time (UTC)21:33
PlatformNot applicable