Cannot connect win2k pro to win2k domain

I have a upgraded a Windows 98 PC to Win 2000 Pro. But I
was Unable to connect it to the domain. The error appears
after I have supplied the domain username and password.
The error message is “The following error occurred
attempting to join the domain “ELAN”. The network name
cannot be found. I have tried to search from the Microsoft knowledgebase but I can’t find answers.