Q: I have a Windows Server 2008 R2 RDS Licensing Server. Can I install Windows Server 2012 RDS CALs on it?
A: Unfortunately not. It isn't possible to install later version Windows Server Remote Desktop Services (RDS) CALs on an RDS licensing server. This means Windows Server 2012 RDS CALs can't be installed on a Windows Server 2008 R2 RDS licensing server. You will need to upgrade the licensing server to Windows Server 2012 to enable installing the 2012 RDS CALs.