Dears I am in the process of upgrading or CCR hosted on Windows 2003 Server to Exchange SP2, i read all the documents about upgrading but my concern is do we have to extend the schema by running Setup.com /PrepAD before running the Setup.com /m:upgrade , some articles says it is a must and some says the upgrade will do it automatically and others say no please advice me

Hi, Personally, I think it is best practice to always prep AD before installing a major upgrade. If there is some time between the AD preparation and the upgrade of Exchange, you can be sure that AD prep is fully replicated between the domain controllers. On the other hand, if you have only one domain controller, you can just start off with setup.com /m:upgrade.

Thanks WoCom