I am trying to help a local charity. They currently have an NT4 server, 2 Windows 2000 servers, and 1 Windows 2003 server. The NT4 server is their PDC, and in fact the only server acting as a domain controller. The others are set up as member servers in their domain, but don't handle log ins, etc. The NT4 server is about out of hard drive space to the point where upgrading to windows 2000 is infeasable. They have purchased another Windows 2003 server, and plan on retiring the NT4 server completely. What would the best path be to accomplishing this? Is it possible to promote a windows 2000 server to a bdc, then demote the nt4 server and promote the windows 2000 server to pdc? Active directory could be done later, but I think it would have to be done after the NT4 server was out of the mix. This organization works 7 days a week (it is the local Humane Society animal shelter) and can't have any network downtime. I am looking for the quickest way to retire the NT4 server and install the Windows 2003 server while retaining their network domain name, user accounts, etc. Any suggestions would be appreciated.