Wait a second. Let me see if I have this right. You had 2 domains, and you could log into either one on 2 servers by typing in the admin user name, password, and selecting the domain you wanted from the Domain drop-down box. Right?
Now, one of those 2 domains is now gone. Now when you try to log into one of the servers, it takes forever (at least 5 mintues, from what I remember from seeing this before) to get the single remaining domain up and to log in.
Is that the situation?
Ok. That is easy.
The domain that remains still has a Trust built into it, pointing to the removed domain. You see, the 2 domains both had a 2-way Trust, pointing to each other.
Now that the 2nd domain is gone (probably by removing the PDC from the 2nd domain and reinstalling NT on it, I would guess), the remaining PDC is still configured to Trust this domain. And it is gonna look for it when clients try to log in.
You need to go to the PDC of your remaining domain, open up User Manager for Domains on it, click Policies -> Trust Relationship, then Remove all Trust references to the 2nd domain.
Click Ok, close UMforD, and then reboot a client, just to clear out everything (if you can reboot the PDC, so much the better).
That should take care of it.
hope this helps