The simple answer is to use the ForensIT user profile wizard --- what Microsoft should have come up with in the first place. Works great;
1. Change client Exchange server to the correct new server.
2. Convert system from domain to workgroup and reboot. (make sure you have a local admin account!)
3. run the ForensIT tool to connect back to the domain. It finds the profile.
Simple! No stupid
http://connect, no screens of empty drop-down menus.