Thanks to WinInfo subscriber Jason Dishop for the tip: Microsoft has posted a new hot-fix for Windows NT 4.0 Service Pack 3. Dubbed the "LM Authentication" hot-fix, it fixes a bug in the Windows NT Registry that requires clients accessing a server to send two types of authentication in certain situations. If a Windows NT Server currently requires Lan Manager (LM) Authentication, this bug forces the client trying to access the server to use LM Authentication _and_ Windows NT authentication, slowing the connection process. The hot-fix alters the Registry to support LM-only authentication

You can download this hot-fix from the Microsoft FTP site