I presently have 3 Domian Controllers, 2 DC's with Windows Server 2003 32bit and 1 DC with Windows Server 2003 64bit. I also have 1 Exchange Server 2003 and 1 SQL Server 2000 servers on my network. I want to upgrade/migrate Active Directory to Windows Server 2008 R2 64bit. What are my options for this upgrade/migration?? Pre-installation tasks?? Post installation tasks?? Will the Exchange 2003 and SQL 2000 servers be an issue?? I also have a brand new server with Windows Server 2008 R2 64bit installed that I want to use as a new Domain Controller and retire one of the existing Windows Server 2003 32bit Domian Controllers.