Q. How do I disable LanManager challenge/response in NT?
A. Windows NT Servers with Service Pack 4 and above support three authentication types,
By default when a client connects to a server both LM and NTLM are used in case the server does not support NTLM however LM is far weaker than NTLM so you may wish to disable LM for security reasons.
Editing the registry key described allows the client to select which authentication is will use but ensure is NTLM2 is select SP4 is applied to all servers. The setting below is required on the clients and servers so you may wish to automate this via a logon script or policy
For more information on deploying see http://support.microsoft.com/support/kb/articles/q147/7/06.asp
This FAQ is copyright © 1999 John Savill (SavillTech Ltd). No part of this document should be reproduced, distributed or altered without my written permission. Contact Information.