I am attempting to migrate from WinNT 4.0 domain to Win2003. I am also trying to change domain names while doing this. I am trying to setup a trust relationship between the 2 domains so that I can migrate services. I am getting the following error when trying to setup the 2-way trust between new Win2003 DC and existing WinNT 4.0 PDC: "The name you specified is not a valid Windows domain.." I am assuming that I need to do some more work in setting up NETBIOS name resolution on the Win2003 DC to be able to see the WinNT 4.0 domain. I see old references to this but I am still having trouble. I have read the MS KB articles on the subject. ANy help would be appreciated. Thanks, Ed

You will need to be sure DNS knows about both domain and you will most likely need to install WINS on both domains and inform each WINS server about the other domain. NT4 isn't all that savy with DNS and uses WINS for this. It's been awhile since I've had to do this, but I've done it and I know it works. You are right though, it's a NetBIOS issue.