An upcoming project I have at work is to migrate our Microsoft Exchange 2007 Server to Microsoft Exchange 2010. There is no direct upgrade from 2007 to 2010, and my Exchange 2007 server is running Windows Server 2003 x64.
At a high level, in order to upgrade, I will need to install new temporary server running Windows Server 2008 and Exchange Server 2010. I will then have to migrate the user mailboxes to the new temporary server. Once the migration is complete and Exchange 2007 is no longer being used or needed, I can then reinstall the operating system and install Exchange 2010 on the old machine. From there, I would move the mailboxes one more time from the temporary Exchange 2010 server to the permanent Exchange server.
I am lucky in that my migration is pretty straight forward and there isn’t more than a couple of dozen mailboxes to move. Hopefully it goes well.