If I upgrade an NT server to 2003. Then replicate the changes to another server and disconnect the first server, will the client computers have to rejoin the domain? I would keep the same domain name.

I found that when i migrate using the admtv2 tool and keep the same domain name I still have to rejoin the clients to the network.

So I need to know if its the same with an upgrade.

I think u better migrate, upgrading from NT to Win 2003 , I dun think it is an easy task at all.

I'd suggest looking on the Microsoft web site for advise and guidance, they usually have very detailed upgrade documentation. Given the impending demise of NT4, then I expect there's lots of info.

Usually they suggest building a new domain controller in the existing domain, then retiring the old NT PDC. If you do it this way, then the domain details remain constant and no rejoining will be required.

So if I upgrade the PDC to a 2003 server, do I have an option to append a .local onto my domain?

currently its just called "domain"
I want it called "domain.local"

If I can change the domain name will that mean my 2000 and XP machines that use DNS need to rejoin the domain? And wil the legacy systems using netbios still be able to connect without rejoining the domain?

ok and ive got backups too incase ur wondering.

Also once I have upgraded my NT domain to a 2003 one i will replicate these changes to another server and disconnect all but this one.

Microsoft has a basic overview HERE (http://www.microsoft.com/downloads/details.aspx?FamilyID=e92cf6a0-76f0-4e25-8de0-19544062a6e6&DisplayLang=en)

Their windows server 2003 website also has more information on what you want to do. Windows server 2003 was put out there to push people away from NT 4.0, not to compete with windows 2000. You should be able to do it. A migration will certainly be easier than an upgrade, but it's deffinently possible to upgrade.