Microsoft Knowledge Base Article 891122 contains the following summary and introduction:
SUMMARYThis 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.
INTRODUCTIONThis 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.|