I have exchange 2007 2 node SCC cluster active/passivei am trying to add a 3rd activr node but its giving me this errorMailbox Role PrerequisitesCompletedElapsed Time: 00:01:15Clustered Mailbox Server PrerequisitesFailedError:Clustered Mailbox Server installation cannot continue: Unable to install a SCC clustered mailbox server. Cluster continuous replication cannot be combined with a single copy cluster. There is already at least one CCR clustered mailbox server installed. Help plzzzzzzzzzzzzzzzzz

wierd, it seems like the install thinks you have a CCR cluster not a SCC one. What's the setup log say, are you sure its a SCC?

i am sure because i was taking snapshots while installing and it shows that its SCC !!!!!

If you do Get-MailboxServer what is the value of the ClusteredStorageType?

Dear all i reinstalled everything and the cluster is working fine thank you alot all