When a client uses Windows NT LAN Manager version 2 authentication (also known as NTLMv2) that is configured with the LmCompatibilityLevel setting to 3 or higher to make a connection to a server running Windows NT 4.0 before a console user has logged on interactively or some other client has performed network logon using LAN Manager or NTLMv1 authentication, one of the following symptoms may occur on the server:
- The server may generate an "access violation" error message, possibly
relating to the LSASS service. This may occur on both the server and the
client during startup, especially during periods of heavy network logon
- The domain name field may not appear on the logon screen of the server even though the user name and password fields do. You may not be able to log on to the domain because this indicates that the domain controller cannot be found.
- Your logon attempt may not work, and you may receive the following error message:
The system cannot log you on (C0000037). Please try again or consult your
This behavior occurs because the Windows NT LAN Manager version 2 (level 3+) logon is received and processed by the server before the NlSamInitialize
function is called, causing an "Access violation" error message. Also, at this time Lsass.exe generates a "STATUS_PORT_DISCONNECTED" error message, which prevents subsequent logon attempts from succeeding.
Windows NT Server or Workstation 4.0
To resolve this problem, obtain the latest service pack for Windows NT 4.0 or
the individual software update. For information on obtaining the
latest service pack, please go to:
how to obtain the latest windows nt 4.0 service pack
For information on obtaining the individual software update, contact Microsoft
Product Support Services. For a complete list of Microsoft Product Support
Services phone numbers and information on support costs, please go to the
following address on the World Wide Web:
Windows NT Server 4.0, Terminal Server Edition
To resolve this problem, obtain the latest service pack for Windows NT Server 4.0, Terminal Server Edition. For additional information, click the following article number to view the article in the
Microsoft Knowledge Base:
How to Obtain the Latest Windows NT 4.0 Service Pack
Microsoft has confirmed that this is a problem in Windows NT 4.0 and Windows NT Server 4.0, Terminal Server Edition.
This problem was first corrected in Windows NT Server 4.0 Service Pack 6 and Windows NT Server 4.0, Terminal Server Edition Service Pack 6.
Windows NT 4.0 supports Windows NT challenge/response (or Windows NT LAN Manager challenge/response) as a method of authentication, along with Basic Authentication and Anonymous Access. Microsoft has developed an enhancement to NTLM called Windows NT LAN Manager version 2 which uses a 128-bit password-derived key and significantly improves session security mechanisms.
For more information about Windows NT LAN Manager version 2, please click the article number below to view the article in the Microsoft Knowledge Base:
How to Disable LM Authentication on Windows NT
This behavior may not occur when the following situations circumvent the issues involved:
- When a server service that runs using a user account starts before the first non-anonymous logon.
- When a user interactively logs on to the server console before the first non-anonymous logon occurred.
- When a client computer is not configured to send Windows NT LAN Manager version 2 only (level 3) as the first non-anonymous logon