We are trying to install Exchange Server 2013 in an Active Directory domain environment where Exchange Sever 2010 RTM was installed before; they have removed the Exchange 2010 RTM server without following proper uninstallation method. Now we are trying to install Exchange 2013 in the same AD environment, where the installation stops by readiness check with the message "All Exchange 2010 servers in the organization must have Exchange 2010 Service Pack 3 or later installed" Is there any method to remove all other existing Exchange 2010 RTM data from the domain controller and prepare the Active Directory domain for Exchange Server 2013?

Hi, Either you have to recover the Exchange 2010 RTM and then install sp3 before installing Exchange 2013. Or you have to install Exchange 2013 on a new AD forest. If it is a test environment I would recommend the second one.Kottees : My Blog : Please mark it as an answer if it really helps you.

Thank you Imkottees. No, this is not a test environment. Someone did that mistake, and we have to deploy Exchange 2013 on the same Active Directory forest.

You will need to recover the 2010 server and then remove it cleanly or recover it and upgrade to 2010 SP3 then use the 2013 CU1 media for your installation. Anything else (like removing objects using ADSIedit) is not supported. Cheers, Steve

Yes, i would go with Steve. better recover 2010-->upgrade to sp3-->install 2013-->migrate it. At the end you will have good exp in migration ;-)Kottees : My Blog : Please mark it as an answer if it really helps you.

Hi M, Any updates?Frank Wang TechNet Community Support

Hi all, Thanks for your prompt support. I have created a lab with the same environment, like my customer made mistake by removing the Exchange 2010 RTM. So far, I have repaired Exchange 2010 RTM on a new server and upgraded it to Exchange Server 2010 SP3, all went ok. Now im planning to remove the Exchange 2010 SP3 systematically from control panel and install Exchange Server 2013 as a fresh on a different server running Windows Server 2012. I will post my updates here.

Finally im over with it. Recovered RTM, Upgraded to SP3 and then Uninstalled it. (Though upgrading to service pack 3 was not necessary in this case but yes I had a plan to migrate it to Exchange 2013. After successfully uninstalling it, deployed Exchange Server 2013! All when perfectly...!!