When you attempt to join a Windows 2000-based computer to a Microsoft Windows NT 4.0-based domain, you may receive the following error message:
The following error occurred attempting to join the domain "domainname":The account is not authorized to login from this station.
This behavior can occur because the Local Group Policy, specifically those in the Computer Configuration\Windows Settings\Security Settings\Local Policies\Security Options folder have a restrictive setting.
Some of the policies that may cause this behavior are:
Digitally sign client communications (always)
Digitally sign server communications (always)
Digitally sign server communications (when possible)
LAN Manager Authentication Level set to Send LM and NTLM - use NTLMv2 session security if negotiated
Secure channel: Digitally encrypt or sign secure channel data (always)
Secure channel: Require strong (Windows 2000 or later) session key
To work around this behavior, set the values back to what they would be if a clean install had occurred.
Examine the preceding policies and set them back to their default settings.