http://blogs.technet.com/b/jribeiro/archive/2009/10/02/exchange-server-2007-service-pack-2-what-s-new-and-how-to-upgrade.aspxNow that Service Pack 2 is out there is a lot of conversation around what to upgrade first and, how to upgrade when and if using Clustered Mailbox Servers. The installation order is, though this is not : - Hub Transport Server Role - Client Accessen-USTelligent Evolution Platform Developer Build (Build: 5.6.50428.7875)