Active Directory Federation Services 2.0 helps IT enable users to collaborate across organizational boundaries and easily access applications on-premises and in the cloud, while maintaining application security. Through a claims-based infrastructure, IT can enable a single sign-on experience for end-users to applications without requiring a separate account or password, whether applications are located in partner organizations or hosted in the cloud.
The Windows Server 2008 R2 setup package for AD FS 2.0 was updated on 1/5/2011. This updated package contains hotfixes that will prevent the errors described in the following support articles from occurring whenever AD FS 2.0 is installed on a server running the Windows Server 2008 R2 operating system:
Get the update here