I am needing to transition from Exchange 2003 to Exchange 2007. I understand I need to bring up a separate box that is running 64bit OS and Exchange 2007. However I want my final state to be back on the original server. IE I will wipe and reinstall the original box with 64 bit OS and Exchange 2007. Is there any documentation on this? What are the gotchas with doing this.....The reason I want to be back on the original box is hard drives. I have a bunch of RAID 10 drives on the original box....Thank you in advance.

If you manage to transition from E2003 to E2007 then move to another E2007 is almost the same thing. Move mailboxes, replicate PF, change OAB etc.

Lasse,Thank you. What are the ramifications of having two E2007 running at the same time in the same domain and same forest? Is this even allowed?

Dear customer: Thanks for Lasses reply. He is right. Of course, you can run two Exchange servers 2007 in the same domain and same forest at the same time. Transition is the scenario in which you upgrade an existing Exchange organization to Microsoft Exchange Server 2007. To perform the transition, you must move data from the existing Exchange servers to new Exchange 2007 servers. For example, when upgrading from an Exchange Server 2003 or Exchange 2000 Server organization to an Exchange 2007 organization, you perform a transition. When transitioning to Exchange 2007, you cannot perform an in-place server upgrade on an existing Exchange server. Instead, you must install a new Exchange 2007 server into the existing organization, and then move data to the new Exchange 2007 server. The transition process happens in several phases. In each phase, you introduce individual Exchange 2007 server roles and transport features. At the conclusion of each phase, the organization will have coexistence of Exchange 2007 with Exchange 2003 or Exchange 2000 and will be running in a supported coexistence mode. The end-to-end process is designed to maintain messaging functionality and stability throughout the transition process. For more information about upgrading to Exchange server 2007, please refer to the following documents: Upgrading to Exchange 2007 http://technet.microsoft.com/en-us/library/bb124008(EXCHG.80).aspx Hope it helps. Rock Wang - MSFT