Windows 2000 RPC Unavailable

I just installed Windows 2000 Server and tried to make my server a primary domain controller for a child domain under an existing, and working, domain. When you go through the steps through the Active Directory Wizard, it asks you to log onto the existing domain and when I do, I get the error that “Could not connect to domain, RPC Unavailable”. I can’t even join another domain. I later reinstalled Windows 2000 Advanced Server and got the same errors. Any help? Thanks, Jeremy