Active Directory Federation Services Registry Settings
Applies To: Windows Server 2008, Windows Server 2008 R2
When using Active Directory Federation Services to allow access to protected documents from a trusted domain or forest, registry keys can set the federation home realm of the client computers in that forest. It must be set to the client’s home AD FS server FQDN and path in clients on the Accounts side of a federation trust.
FederationHomeRealm: This registry key allows you to specify the federation home realm.
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSDRM\Federation
REG_SZ: FederationHomeRealm
Value: < the federation service URI>