AD RMS installation error

Error Msg: Attempt to configure Active Directory Rights Management Server failed. The AD RMS installation could not determine the certificate hierarchy. If the AD RMS service connection point (SCP) you need to use is registered in Active Directory but is not valid, revise it to make it valid, or create a new SCP, and install AD RMS again…

If you are receiving this error, it’s probably because of a previous installation (or failed installation) of AD RMS.  When AD RMS is installed, the wizard reaches out to your Active Directory controller and creates a Service Connection Point (SCP) there.  Later attempts to install will fail because they cannot overwrite the existing SCP.  You’ll simply need to delete it.  A poster named Sally.Mark contributed the below which worked for us:

Just wanted you to know that I was able to solve this problem. For anyone else who may someday come across this problem. What I did to solve it was, on AD computer, I opened the run command and then ran  ADSIedit.msc.   The ADSI edit MMC window popped up and I browsed down to Configuration and then expanded the first node, then expanded Services and then I deleted the SCP that said  CN=RightsManagementServices.  I deleted the whole thing and subfolders and then I went back and reinstalled AD RMS on my server. This time it worked perfectly.

Source: http://social.technet.microsoft.com/Forums/en-US/winservergen/thread/4feaa2d2-afb2-4d7c-8414-fdf44a13d0bb/