Kamiru,
I am not sure that I follow what you are saying here.
You have a WIN2000 Active Directory environment that had only one Domain
Controller. You added a second domain controller. This was a very wise
thing to do - generally speaking. However, your users can not authenticate
against the original DC anymore. I suppose that you have verified this by
going to user workstations and entering the 'set' command ( or specifically
'set l' )?
Assuming that you did not create a new domain when you dcpromo'd the second
DC ( but then the problem would be vice-versa ) I might suggest that there
is a replication issue between the two DCs.
Let's look at a couple of things first:
Are both DCs running DDNS? Are both DCs also Global Catalog Servers? I
assume that we are talking about one Site? I assume that DNS is indeed set
up correctly 9 regardless if both DCs are running DNS or not )?
Let's try installing the Support Tools on both DCs and running netdiag /fix
on both of them and then let's run dcdiag /c /v and netdiag /v as well as
repadmin /showreps and repadmin /showconn.
Additionally, you might want to take a look at the following MSKB Article:
http://support.microsoft.com/?id=249256
HTH,
Cary