I started seeing this on Win2K and Win2K3 domain member servers after changing the value of "HKLM\System\CurrentControlSet\Services\Netlogon\Parameters\NT4Emulator" from 1 to 0 and then having to set it back when user logons started failing. I had to remove and add servers in order to fix things. All the tech docs I reviewed made it seem like a pretty straight forward change. Clearly, I missed a dependency somewhere.
Error: "There are currently no logon servers available to service the logon request." - In my case, removing the computer from the domain and re-joining it solved the problem.
Error: "There are currently no logon servers available to service the logon request." - The problem was caused by Netlogon trying to load before the DNS server had started, therefore it did not know how to connect to the PDC. Modify the registry to make Netlogon dependant on DNS. Go to this key: “HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Netlogon" and modify the “DependOnService” string adding DNS after LanmanWorkstation.
From a newsgroup post: "I think I have solved the problem. The problematic server was hosting a second primary DNS zone for the domain and pointing to itself. Making the zone secondary and pointing the server to the primary zone, seems to have resolved the errors for me".
From a newsgroup post: Error: "No suitable domain controller is available for authentication in this domain." Restart the NETLOGON service on Domain controller. Make sure that client machine points to the correct DNS server. Make sure that the DC is registered by itself with the DNS server. Look at the SRV resource record.