If you have already have ISA Server 2006 Enterprise Edition installed and you are trying to installing ISA Server on another server and configuring it as a replica of the Configuration store, you may get the following error on Windows Server 2003 R2:




Setup then exits and you are unable to complete the installation. This usually happens if there was a previous failed installation from the machine that you're trying to join to the array. You will need to cleanup the values related to the server you're installing from the ADAM installed on your first configuration store, which stores config information for the array.

A simple solution to this is to ensure that both nodes are running Windows Server 2003 R2 and then edit the ADAM to remove the orphaned server on which installation is failing:

1. Open \Windows\ADAM\ADAM-ADSIEDIT.msc on the existing ISA Config Storage server.
2. Navigate to CN=Configuration, CN=Sites, CN=Default-First-Site-Name,CN=Servers.
3. Delete the server on which you have the installation problem.

Re-run the installation, it should succeed now.