I am migrating a clients main office from Windows 2000 SBS to Windows 2003 Standard Server Edition and Exchange 2003. I need to try and keep all the existing AD objects intact - including the Exchange Mailboxes. The Windows 2000 SBS server will then be reloaded with Windows 2003 Standard Edition, Exchange 2003 Enterprise edition, and SQL2000. Is there a supported and/or built in tool for this?

I was looking to use a seperate Windows 2003 Standard "loaner" server to migrate the AD and data before the SBS to 2003 reload on the production server. A bonus solution for connecting 10 remote offices with established VPNS, 15 or fewer users, and servers on seperate Win2k domain controller would also be helpful.

Otherwise please advise of best practice(s) - keeping in mind that a creation of a new AD at the main office is not desired due to labor and budgetting constraints. Thanks in advance for any assistance.