ALL YOUR USER INFORMATION WILL BE ERASED if you uninstall Active Directory. Your network will slow down if all the computers on your network (clients) are NT4, especially, if they logon to WIN2K with roaming profiles. if you are gonna move to win2k server then i suggest you migrate to win2k pro for your client computers--the network speed wiil increase. you probably are gonna have to install WINS on your win2k advance server and then tell your client computers on the network where the WINS server is. that should speed things up when doing name resolution.