When you upgrade Windows NT 4.0 BDC, restart the newly upgraded Windows 2000 Server, and begin the DCPromo process, you receive:
This error is reported when you select the Leave as member server option, but DCPromo works if you select the Make a Domain Controller option.
This behavior is probably the result of invalid entries for domain controllers in the %SystemRoot%\System32\Drivers\Etc\LMHOSTS file.
To fix the problem, correct or remove the invalid entries.
NOTE: The incorrect entry is probably the first n.n.n.nBDCname #PRE #DOM:DomainName entry, where n.n.n.n is the IP address.