Hi there, We currently have 1 Front End & 2 Back End Exchange 2003 Ent servers, and we are considering upgrading to 2007. My question is can you upgrade from 2003 Ent Ed. to 2007 Std? Thanks, Guy

Hello Guy, 64bit edition of Exchange 2007 should be installed on 64bit hardware so you need new hardware and upgrade is not an option. Install new hardware and install fresh Exchange 2007 server on it... Installation sequence should be CAS -> Hub -> Mailbox if you are planning different roles on separate servers.

Hello Amit, I am aware of the 64bit hardware, I am more concerned with the versions of the Exchange, and do I have to migrate users all at once or can I still have an Exchange 2003 Ent in the mix with 2007? Thanks, Guy

Yes Guy, you can move from Ex2003 Ent to Ex2007 STD. Actually, you can migrate to any edition of Exchange 2007 depending on your requirement. Exchange Server 2007: Platforms, Editions, and Versions Yes, you dont have to move all users at once and you can still be in mix/co-existence mode. Coexisting with Exchange Server 2003 and Exchange 2000 Server Managing Exchange 2003 Settings in a Coexistence Environment