The system can not log you on (C000019B).... I joined the domain successfully but after upgrading to a newer version of the Samba code I get the message, "The system can not log you on (C000019B), Please try a gain or consult your system administrator" when attempting to logon. This occurs when the domain SID stored in private/WORKGROUP.SID is changed. For example, you remove the file and smbd automatically creates a new one. Or you are swapping back and forth between versions 2.0.7, TNG and the HEAD branch code (not recommended). The only way to correct the problem is to restore the original domain SID or remove the domain client from the domain and rejoin. Hi, I ve upgraded my samba version from 2.0.7 to 2.2.5 to accept Windows XP and NT client on my samba domain, and it works fine.. But, unfortunately, my NT4 does not recognize my PDC anymore.. getting the C000019B error.. So, as you say, i should get the secrets.tdb back ( because since the 2.2.4, the MACHINE.SID changed to secrets.tbd ), but i ve tried, but didnt changed anything on my NT4.. I dont know if it is a real "bug", but i ve looked everywhere on the Net and couldnt find any answers.. and as 2.2.5 is a quite new version, i thought... If it is not.. answer me please! :-) Thanx for your help! And keep going :-)