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Article ID: 891122 - Last Review: September 14, 2012 - Revision: 7.0

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This article describes an update to the Microsoft Windows Media Digital Rights Management (DRM) system. You can use this update to make the Windows Media DRM system more robust.


This update improves the robustness of the Windows Media DRM system. It also adds more integrity checks to the DRM system by installing two components on end users' computers. License issuers can verify that each user's computer has been updated before issuing or renewing licenses. Updates for the end user require the following actions:
  1. Updating the Windows Media Format run-time components.

    Note Applications that are based on the Windows Media Format SDK do not have to be modified. This update affects only the redistributable run-time components. However, ISVs are encouraged to include the new run-time components with their application.
  2. Re-individualizing the DRM component in their application.

More information

Software update information

A supported update is now available from Microsoft, but it is only intended to correct the problem that is described in this article.

To resolve this problem, contact Microsoft Product Support Services to obtain the update. For a complete list of Microsoft Product Support Services telephone numbers and information about support costs, visit the following Microsoft Web site:;[LN];CNTACTMS (;[LN];CNTACTMS)
Note In special cases, charges that are ordinarily incurred for support calls may be canceled if a Microsoft Support Professional determines that a specific update will resolve your problem. The usual support costs will apply to additional support questions and issues that do not qualify for the specific update in question.

Windows Media Format 9.5 Runtime

The following file is available for download from the Microsoft Download Center:
Collapse this imageExpand this image
Download the WindowsMedia-KB891122-x86 package now. (
File information
The English version of this update has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time tool in Control Panel.
   Date         Time   Version         Size       File name
   28-Jan-2005  18:44       294,912  Blackbox.dll
   28-Jan-2005  18:44  10.0.3790.3802    164,864  Cewmdm.dll
   28-Jan-2005  18:44       258,296  Drmclien.dll
   28-Jan-2005  18:44        96,768  Drmstor.dll
   28-Jan-2005  18:44       173,304  Drmupgds.exe
   28-Jan-2005  18:44       502,272  Drmv2clt.dll
   28-Jan-2005  18:44         6,656  Laprxy.dll
   28-Jan-2005  18:44        96,768  Logagent.exe
   28-Jan-2005  18:44       142,336  Msnetobj.dll
   28-Jan-2005  18:44  10.0.3790.3802     25,088  Mspmsnsv.dll
   28-Jan-2005  18:44  10.0.3790.3802    173,568  Mspmsp.dll
   28-Jan-2005  18:44       364,784  Msscp.dll
   28-Jan-2005  18:44  10.0.3790.3802    315,904  Mswmdm.dll
   28-Jan-2005  18:44       221,184  Qasf.dll
   28-Jan-2005  18:44  5.2.3790.1230      47,104  Uwdf.exe
   28-Jan-2005  18:44  5.2.3790.1230      15,872  Wdfapi.dll
   28-Jan-2005  18:44  5.2.3790.1230      38,912  Wdfmgr.exe
   28-Jan-2005  18:44       396,528  Wmadmod.dll
   28-Jan-2005  18:44       716,288  Wmadmoe.dll
   28-Jan-2005  18:44       224,768  Wmasf.dll
   28-Jan-2005  18:44  10.0.3790.3802     28,160  Wmdmlog.dll
   28-Jan-2005  18:44  10.0.3790.3802     33,792  Wmdmps.dll
   28-Jan-2005  18:44       335,872  Wmdrmdev.dll
   28-Jan-2005  18:44       290,816  Wmdrmnet.dll
   28-Jan-2005  18:44       150,016  Wmidx.dll
   28-Jan-2005  18:44     1,027,072  Wmnetmgr.dll
   28-Jan-2005  18:44       774,904  Wmsdmod.dll
   28-Jan-2005  18:44     1,119,744  Wmsdmoe2.dll
   28-Jan-2005  18:44       819,200  Wmsetsdk.exe
   28-Jan-2005  18:44       413,944  Wmspdmod.dll
   28-Jan-2005  18:44       940,544  Wmspdmoe.dll
   28-Jan-2005  18:44     1,218,808  Wmvadvd.dll
   28-Jan-2005  18:44     1,512,448  Wmvadve.dll
   28-Jan-2005  18:44     2,370,296  Wmvcore.dll
   28-Jan-2005  18:44       895,736  Wmvdmod.dll
   28-Jan-2005  18:44     1,003,008  Wmvdmoe2.dll
   28-Jan-2005  18:44  5.2.3802.3802      61,952  Wpdconns.dll
   28-Jan-2005  18:44  5.2.3802.3802     114,176  Wpdmtp.dll
   28-Jan-2005  18:44  5.2.3802.3802     331,776  Wpdmtpdr.dll
   28-Jan-2005  18:44  5.2.3802.3802      66,560  Wpdmtpus.dll     
   28-Jan-2005  18:44  5.2.3802.3802     331,264  Wpdsp.dll
   28-Jan-2005  18:44  5.2.3802.3802      10,752  Wpdtrace.dll
   28-Jan-2005  18:44  5.2.3802.3802      18,944  Wpdusb.sys
   28-Jan-2005  18:44  5.2.3802.3802      38,912  Wpd_ci.dll

Software update removal information

To remove this update, you must uninstall the Windows Media Format Runtime by using Add or Remove Programs.
During the license acquisition process, content services can detect whether their end users have updated their computers by checking for component versions. Using the Windows Media Rights Manager SDK on the licensing server, the content service can retrieve version information from the client and then determine how to continue. The license server can determine whether the client has the update by using one of the following methods:
  • Determine the version of the user's operating system.
    At first, the update to the Windows Media DRM system is available only to users of Microsoft Windows XP. Use client-side code to determine the version of the user's operating system.

    Content services may choose to issue licenses to computers that the update is not yet available for. Or, content services should notify their users that licenses will not be available until the DRM run-time component for their operating system becomes available.
  • Determine the version of the Windows Media Format run-time components on the client.
    Determine the version of the Windows Media Format run-time component that the user's player is based on. Use the WMRMChallenge.ClientVersion property to retrieve this value. An updated client has version To install the updated run-time components, redirect the user to the URL that is mentioned in the "More Information" section.
  • Determine the security version of the DRM component for individualization.
    Determine the security version of the DRM component. The version number indicates whether the client must individualize its player. Although the Windows Media Rights Manager SDK provides several ways to determine the security version, we recommend that you use the WMRMLicGen.GetClientVersion method because the resulting value is digitally signed. This digitally signed value cannot be tampered with. The value for the pvarVersion parameter of this method indicates the security version a.b in the format:
    a*256 + b (For example, a security version of 2.4 returns a value of 516.)
    An updated client has a security version of 2.5 or a later version. If you see a value that is less than or equal to 516, you know that the client requires individualization. You can redirect users to the following Microsoft Web site to initiate individualization: (
Note Before the licensing servers can determine the versions of client components, you must update the configuration information on the licensing servers. To do this, visit the following Microsoft Web site and then click Download the latest License Server information: (
You must perform this update on each computer that is running Windows Media License Service.

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

Applies to
  • Windows Media Format 9.5 Software Development Kit
  • Windows Media Player 10
  • Microsoft Windows Media Player 9 Series
kbresolve atdownload kbfix kbqfe KB891122
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