Hi,I have a problem with MBX cluster installation - I configured the Failover Cluster consisting of two Windows Server 2008 Ent. Ed. servers with file share witness located on CAS server. Ater that I tried to install Exchange 2007 SP1 x64 on the first node of the future cluster and I ran into a problem (the idea is to form a CCR cluster):- I did not configure appropriate permissions for the machine account of the failover cluster in AD so that it could create a machine account for Mailbox server in AD during the installation.The result was a failed MBX active cluster node installation, and there was no option to go back and try the installation again after solving the problems with AD permissions.I believe that he problem is now solved since I have created a computer object in AD and delegated Full Control permission to my failover cluster machine account. The failover cluster console now shows MBX as an active application of the cluster.The question is: What is the recommended procedure for starting a new MBX cluster server installation after the first attempt failed?Is it necessary to clean up exchange server objects from AD? Is there any document that details these steps?Any help would be appreciated,Thank you,Best RegardsMilan Banjac

can you try to use Add/Remove programs and simply uninstall the faulty installation? take a look at this http://msexchangeteam.com/archive/2007/05/21/439529.aspx have seen faulty installations that start working again when the watermark registry key is deleted.

Issue description: How to deploy exchange 2007 after one failed installation As Lasse said, please remove all traces belong to the old installation before you start again If you cannot remove Exchange 2007 by using Add/Remove Programs, you can use Registry Editor to remove the Exchange entries from the registry 1. On the install CD go to the root right click on ExchangeServer.MSI and right click to choose Uninstall 2. Stop and disable the Exchange 2007 services 3. Use Registry Editor to remove the Exchange registry keys a. Click Start->Run->regedit b. Expand to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Exchange c. Right-click Exchange, and then click Delete. Click Yes in the Confirm Key Delete dialog box d. Repeat steps b and c for each of the keys containing keyword Exchange or MSEXchange under HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services 4. Remove and reinstall IIS component 5. Remove the Exchange 2007 server from Active Directory a. Launch ADSI Editor b. Expand to Configuration Container->CN=Configuration, DC= Domain_Name ,DC=com->CN=Services ->CN=Microsoft Exchange->CN= Your_Organization_Name->CN=Administrative Groups ->CN= Your_Administrative_Group_Name->CN=Servers c. Right-click old Exchange 2007 server object, and select Delete d. Click Yes in every jumped windows that prompts you to confirm the deletion References: How to remove Exchange 2007 from a computer How to completely remove a Exchange server or the entire Exchange organization

Dear James and Lasse,Thank you for your answers.I have managed to uninstall, remove from registry, remove from AD, remove CMS record from DNS and then install again.Could you please make a comment regarding why the installation failed - we have a GPO that does not allow creation of computer accounts in computers OU without special permissions.So, do you agree with me that Exchange installer, when one chooses to install the first (active) node of CCR cluster, should check the appropriate permissions for creating CMS account in AD as part of prerequisite check?Anyway, I was not able to find about this prerequisite in documentation.Thank you for your help.Regards,Milan Banjac

When installing Exchange active node, the creation of the CMS is done in the context of CNO. I would create the CNO (cluster network object) in advance, give the user account doing the installation full control of it. Next I would create the CMS computer account. give both the CNO computer and the user doing the installation full control of it. Finally disable both accounts. Then do the CMS installation

Thanks Lasse for your comment,I agree with you. Maybe it would be good to include these steps in the official documentation.Regards,Milan Banjac