Environment Domain Controller OS = 2008 SP1 Exchange Server = 2003 SP2 Problem I have Exchange2003 with SP2 running in my environment which is running fine. I started installation of Exchange2010 (in same environment) which failed in the middle. I thought to remove this un completed installation of Exchange2010 from the Schema. So I tried to remove the un completed Exchange2010 from Program and Feature but facing the below error. I started Exchange2010 installationwith a new name but that activity is also failed with the below error.Now I am in the middle means not able to remove Exchange2010 even not able to install exchange with a very new name Any comment will be appreciated. Thanks. Zahid Haseeb.

Hello Zahid, Similar issue you can follow this Post http://social.technet.microsoft.com/Forums/en/exchange2010/thread/d058717e-bf70-4449-91c2-fa00b47d415f Thanks Mhussain

Hello Zahid, Similar issue you can follow this Post http://social.technet.microsoft.com/Forums/en/exchange2010/thread/d058717e-bf70-4449-91c2-fa00b47d415f Thanks Mhussain

howto delete arbitration mailboxes directly through ADSIEdit.msc ? Second I also feel that the problem is also the following D:\Exchange 2010 SP1>setup /prepareAD Welcome to Microsoft Exchange Server 2010 Unattended Setup Setup will continue momentarily, unless you press any key and cancel the installation. By continuing the installation process, you agree to the license terms of Microsoft Exchange Server 2010. If you don't accept these license terms, please cancel the installation. To review the license terms, please go to http://go.microsoft.com/fwlink/?LinkId=150127&clcid=0x409/ Press any key to cancel setup................ No key presses were detected. Setup will continue. Preparing Exchange Setup Copying Setup Files COMPLETED No server roles will be installed Performing Microsoft Exchange Server Prerequisite Check Organization Checks FAILED Setup is going to prepare the organization for Exchange 2010 by using 'Setup /P repareAD'. No Exchange 2007 server roles have been detected in this topology. Af ter this operation, you will not be able to install any Exchange 2003 or Exchang e 2007 servers. The Active Directory needs to be prepared for Exchange Server and Ldifde.ex e is not installed on this computer. You must install Ldifde.exe by opening Wind ows Powershell, running 'Import-Module ServerManager', then running 'Add-Windows Feature RSAT-ADDS'. Alternately you can restart setup on a domain controller. The Exchange Server setup operation didn't complete. More details can be found in ExchangeSetup.log located in the <SystemDrive>:\ExchangeSetupLogs folder. Exchange Server setup encountered an error. D:\Exchange 2010 SP1>

Exchange Installed successfully. What I did see below 1.) I follow the below link http://www.windowsitpro.com/article/exchange-server/how-to-uninstall-a-stubborn-exchange-server Extract of above link You don't need to worry about the AD schema changes that the Exchange installation made. These changes can't be reversed because you can't delete schema objects and attributes. Even if you could, it wouldn't be a good idea. If you have multiple Exchange servers, the remaining servers need these schema objects and attributes. Plus, if you uninstall your lone Exchange server, the schema objects and attributes that remain won't cause any problems. In fact, if you should later decide to install Exchange again, it would take a shorter time because the schema have been already changed. The server's configuration information in AD can be removed using the ADSI Edit console (ADSIEdit.msc). In Windows Server 2003 and Windows 2000 Server, this tool is one of the Support Tools, which aren't install by default. In Windows 2008, the ADSI Edit console is installed by default. To remove the configuration information, open the ADSI Edit console, and navigate to Services\Microsoft Exchange\ExchangeOrganizationName\AdministrativeGroups\RelatedOrganizationGroup\Serverswhere ExchangeOrganizationName is the name of your Exchange organization. After you locate the server you want to uninstall, simply delete it. Alternatively, you can delete the Microsoft Exchange container altogether. By doing this, you delete the Exchange organization's information in AD. However, be aware that removing a server this way isn't supported by Microsoft unless you're instructed to do so by its Customer Service and Support (CSS) staff. In addition, you run the risk of leaving semi-deleted objects or partially mail-enabled objects in AD. This isn't important if you don't plan to install Exchange into a forest again, but it is important if you do, as you can run into problems. To mitigate these risks, I delete the Microsoft Exchange container after moving the mail-enabled objects to other servers or after deleting them. You can delete the user groups related to the Exchange server, but this step isn't necessary. You should do this only if you want to undo all the changes. You need to delete the following registry keys on the Exchange server: In Exchange 2010 and Exchange 2007, delete the HKLM\Software\Exchange and HKLM\Software\Exchange Server keys. In Exchange 2003 and Exchange 2000, delete the HKLM\Software\Exchange key. In the HKLM\System\CurrentControlSet\Services key, delete the keys that were created for the Exchange Server services. In Exchange 2010 and Exchange 2007, all the keys related to the Exchange Server services start with MSExchange (e.g., MSExchangeIS). In Exchange 2003 and Exchange 2000, most of the keys also start with MSExchange. However, three keys have names that don't include this string. They are IMAP4Svc, POP3Svc, and RESvc. 2.) See the below link http://blog.mattsampson.net/index.php/hub-transport-role-failed-exchange-2010-could-not-find-the-default-administrative-group?blog=1 Extract of above link From the Exchange 2010 install media run the following commands without the quotation marks. “setup.com /prepareSchema” - Prepares the Active Directory Schema for the Exchange installation. “setup.com /prepareAD” - Prepares the Active Directory forest for the Exchange installation. “setup.com /prepareDomain” - Prepares the local domain for the Exchange installation. (If you need more switches to prepare Exchange look here : “Setup.com /helprepareTopology” ) 3.) Reinstall the OS on which we were previously installing the Exchange2010 and getting failed. This may remove all the registeries and all the Exchange folders under programFiles One more important link which helps us http://clintboessen.blogspot.com/2011/09/rms-shared-identity-user.html Any comment will be appreciated. Thanks. Zahid Haseeb.