When you attempt to access a NetBIOS resource on a Down-level client in a Windows 2000 domain, you receive:
\\ComputerName is not accessible. The account is not authorized to log in from this station.
Note: You can browse by IP address, but you cannot browse the resource by using the NetBIOS name.
If you installed Windows 2000 and subsequently replaced it with Windows 98, Windows Millennium, or Windows NT, an invalid computer entry remains in the Active Directory.
To resolve the problem, either remove the invalid computer entry from Active Directory User and Computers, or rename the down-level computer.