Migrating Exchange Server 2003 Enterprise Edition from old hardware to new hardware

Personally I would do the Mailbox Migration, I've done it before and had no issues.

1. Install Windows on the new server & patch it
2. Join it to the existing domain
3. If that server needs to be a domain controller DCPromo it, and add the GC role, etc to it, if doesn't need to be skip this step.
4. Install Exchange 2003, SP2
5. In the Exchange System Manager you should now see both servers.
6. In Active Directory users and customer, Create a new user, when selecting the mailbox part, select the new exchange server
7. Login, and make sure the new user works on the new server.
8. Make sure you are logged off any workstations
9. In Exchange System Manager, move your mailbox to the new Exchange server
10. Login as yourself, open outlook
11. Outlook should detect the mailbox move and reconfigure itself, you shouldn't need to change a thing. You can double check after you confirm its working that the mail server in the account is now the new one
12. If that good, move a couple of users mailboxes.
13. The next day confirm they are good and working and Outlook re-configured them automaticly as well.
14. Move the rest of the users.
15. As long as you leave both exchange servers online, Outlook will connect to the old Exchange server, see the mailbox has been moved and reconfigure itself to the new server.

Your end users shouldn't see a thing. Last time I did it, I left both the old and new Exchange server online for 4 weeks. This give all users time to login to the computers they used. I didn't have to change anyone manually.

1. After that suitable period of time, Stop the Exchange services on the old server
2. Wait a week, make sure everything is still working, if something bad happens, just start the services back up. Send test email from hotmail to your domain, etc.
3. If thats all good, uninstall Exchange from the old server
4. At this point, I would actually stop and leave the old server online as a second DC. It's always good to have 2 DC's on a domain should one fail. Then you don't lose/have to rebuild the whole domain.
5. But if you want to remove it, shut the server down for a week, make sure everyone can still login and everything works. Its way easier to restart the server then to re-promote it if you missed something.
6. Once everything is good and you are sure everything is working, run dcpromo on it again to demote it to a member server.
7. Remove from domain and done

If it goes smoothly your users won't even notice and there will be no downtime except for when you actually are move a users mailbox.

To Quote Evan:

• If the old Exchange Server computer is a domain controller, use DCPROMO to demote it. If it's your only domain controller (shame!), promote a new one first.

Sorry Mate, that's unsupported by Microsoft KB822179

"You can run Exchange Server 2003 on either a member server or on a domain controller. After you install Exchange Server 2003 on a server, do not change the role of the server. For example, if you install Exchange Server 2003 on a member server, do not use the Dcpromo tool to promote the server to a domain controller. Or, if you install Exchange Server 2003 on a domain controller, do not use the Dcpromo tool to demote the server to a member server. Changing the role of a server after you install Exchange Server 2003 may result in loss of some Exchange functionality and is not supported. "

I know you are not going to be using it after, but do you want to put yourself into an unsupported state should something happen and a call to Microsoft be needed?

The question is hard enough to understand, but I think you mean you need to migrate Exchange from one box to the other?

If this is the case, the choice is dependent on if you can take any downtime and how big your mail store is. When we did it, I didn't have the option of downtime. I had to setup a mail frontend to handle request for the clients and then start migrating the individual mail stores across. I could pick times when individual users were likely to be sleeping to do the changes meaning on two people noticed the moves.

If you can take downtime, it is possible to backup Exchange and restore onto the new box. If it doesn't work, you can just power on the old box again.

For the second question, Active Directory is better to spin up on the new box and let it propagate. Once it has, you promote the new box into the primary rolls and remove the old one.