We have an Existing NT4 domain structure with 1 PDC, 3 BDC's, 4 x Exchange 5.5 Servers and 5000 user accounts. The existing PDC's and BDC are used for file-sharing but are too old to run Win2k. Out of the existing 4 Exchange servers one which was the original 5.5 installed server is running WinNT4 and is too old for Win2k the other 3 are all running Win2k.
At the moment we are running 1 main NT4 domain to serve the 5000 users on the LAN but have a trusted link into another NT4 domain over a WAN link. After the upgrade we would still need to maintain the trusted link to allow file-sharing both ways between our new 2003 AD and the existing NT4 domain over the WAN. In the future the NT4 domain over the WAN link will be upgraded to it's own Win2000/2003 AD but will still need to maintain file-sharing with our new domain.
We are looking to install Windows 2003 AD onto 3 new servers which will be for AD/DNS/DHCP use only, and install Exchange 2003 onto the Existing 3 Win2k 5.5 servers migrating the existing 5000 NT & E-Mail user accounts over with the least amount of distuption to the users as possible. Can you give us an idea of the process involved and any problems we may encounter.