I installed a trial edition of windows server 2003 and installed service pack 2. I did not change the functional level, but it appears to be in windows 2000 native mode, although i didn't set that. I'm not interested in changing the functional level downwards, because i know you can't!

But i would like to join the Windows NT 3.51 SP5 to the domain.

I created a computer account on the server and then connected the NT 3.51 computer to the network, but it couldn't pick up an IP address by DHCP. So i set a manual ip address and i was then able to ping the DC from the workstation, but when i tried to join it to the DC, it kept reporting that a DC could not be contacted.
Is there anyway to get round this?
I believe that if i had upgraded the server from NT4.0 server to 2003 server, then it would have been allowed to connect, but because the server was installed from scratch its set the functional level higher than i would have wanted

The main thing i would like to be able to do, at the very least is to store documents on the server from the NT 3.51 server and if possible, put the profile there was well.

Any advice greatly appreciated

You need to run the DC in Win2K mixed domain mode. I'm not sure how you do that, and don't have a Win2K3 box to find out. I'm sure Google will be a big help here.

But it seems that this is only allowed if you upgrade the server from NT 4.0 server.

Strangely though, i was allowed to join an NT 4.0 server from a different domain

The windows 2003 server is in the abcd domain for example, and the NT 4.0 server was in the xyz domain. I put it on the same network and changed the domain of the NT 4.0 server to abcd. After being prompted for my username and password, and a warning about moving computers between domains, the NT 4.0 DC was joined to the abcd domain. I had to restart the computer and type a valid username and password for the existing domain, but it all worked fine.

Going back to my original problem. I can confirm before anyone says it, that i did assign the computer account as a pre-windows 2000 computer.

I wonder, if i turn on the NT4.0 DC, will it allow the older computer to connect to the DC through it???

I'll try it later....

I found this page, which references the domain mode, but it's mostly an ad for the guy's book. Still, it might be worth a trip to the library.

That's the only thing I dug up, which is odd, because I know tools exist. Maybe my Google skills are just weak. AdExplorer might do it. This configuration change seems to be out of the scope for the program, but Sysinternal's tools do tend to err on the side of power, so you never know.

What i don't understand is why the NT 4.0 server, albeit a PDC, was able to join a windows 2003 server in windows 2000 native mode.

When i logged onto the NT4 server with a windows 2003 profile, it didn't look very good, but never mind.

The next question is, if i keep the NT 4 server online, will i be able to join the NT 3.51 workstation to the domain via this server? Hmmmm?

I'm not sure anyone is reading this anymore, but i thought i would come back with an answer that may help other people out.

It should be true that in windows 2000 native mode, the NT4.0 server PDC, should not have been able to join the w2k03 domain, even though the domain administrator should be able to do it. So i can't explain why the NT 4.0 server was able to join, but it was.

I was not able to join the old computer to the domain, so long as the w2k03 server was on the network, because, even if you try to choose the old computer to talk to the NT 4 server, somehow, the NT 4 server must forward the request onto the w2k03 server and it gets turned down. But when i turned the w2k03 server off, then after a short while (about five minutes), the old computer was allowed to join the domain.

Now i can print on printer that is connected to the w2k03 server and access all the shares.
The most important thing for me is to be able to back up the data. i've been putiing some important info on the NT3.51 computer and no means to back it up.
Success!!