[ActiveDir] Nt4 domain controller upgrade to Windows 2000

[Graham Turner]

Apologies if this one has been around before but .. as subject i am looking to acheive the upgrade of a whole load of NT4 backup domain controllers to Windows 2000. it is preferable to use an upgrade method (as opposed to new install) - based on a number of installed applications / services (dhcp, wins, lpr server). it is also intended to change the domain membership of these DC's in the same process. the observed behaviour is that the Windows 2000 setup routine detects its configuration as a DC and generates a "red" warning in a system compatibility report stating that the PDC should be upgraded first. presumably the setup routine must do some sort of query against the PDC to determine its OS version ?? the domain from which these DC's are intended to be migrated is in fact a NT4 domain, and this seems to be critical to the continuance of the setup routine. is it correct that there is no option for the existing domain membership to be modified in this setup routine ?? it seemed to me that the dcpromo routine that initiates at first logon when Windows 2000 starts would be flexible enough that if the administrator so decided to remove any exsiting security information from the original NT4 domain and replace it with the information from an administrator specified domain ?? if this is the case then the available options (given that the upgrade of the PDC to a production domain is by far the least preferable) need to be evaluated; is it a "supported" operation to take the BDC offline from the network, promote it to PDC (merely to allow the setup routine to proceed) which presumably would complete given that the system would not detect any - this begs the question as to the checks that a BDC promotion goes through to complete - is it merely the non-detection of an exsiting PDC or is there a bit more sophistication ?? from here then once the system is running Windows 2000, the dcpromo process can be stopped, and reinitiated once the computer is joined to the network once again as a Windows 2000 member server, and joined to a new domain ? otheriwse it seems to me that the only way of proceeding is to use the "clean installation" method and reinstall all applications / services. on this tack, it seems to me potential issues with the restore of a DHCP server configuration (backed up by taking a copy of the relevant NT4 registry key) to a Windows 2000 DHCP server - is this a supported operation. I will be very appreciative of input from the newsgroup on this one GT