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Microsoft KB Archive/251404

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Knowledge Base

You cannot post data to a non-NTLM-authenticated Web site

Article ID: 251404

Article Last Modified on 12/3/2007


  • Microsoft Internet Explorer 6.0, when used with:
    • Microsoft Windows Server 2003, Standard Edition (32-bit x86)
    • Microsoft Windows 2000 Enterprise Edition
    • the operating system: Microsoft Windows 2000, Server SP1
    • Microsoft Windows XP Professional
    • Microsoft Windows XP Embedded
    • Microsoft Windows NT 4.0
    • Microsoft Windows 98 Standard Edition
    • Microsoft Windows 98 Second Edition
    • Microsoft Windows Millennium Edition
  • Microsoft Internet Explorer 5.01, when used with:
    • Microsoft Windows 2000 Standard Edition
    • Microsoft Windows NT 4.0
    • Microsoft Windows 98 Standard Edition
    • Microsoft Windows 95
  • Microsoft Internet Information Services 5.0
  • Microsoft Internet Information Services 6.0

This article was previously published under Q251404

Important This article contains information about modifying the registry. Before you modify the registry, make sure to back it up and make sure that you understand how to restore the registry if a problem occurs. For information about how to back up, restore, and edit the registry, click the following article number to view the article in the Microsoft Knowledge Base:

256986 Description of the Microsoft Windows Registry


You cannot post any data to non-NTLM authenticated Web sites.


This issue can occur after you visit an NTLM authenticated folder.

Note Microsoft Internet Explorer requires NTLM authentication for all visits after you visit one NTLM authenticated folder.


Warning If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.

To resolve this issue from the client side, use Registry Editor (Regedt32.exe) to add a value to the following registry key:

HKEY_CURRENT_USER/Software/Microsoft/Windows/CurrentVersion/Internet Settings/

Note The above registry key is one path; it has been wrapped for readability.

Add the following registry value:

Value Name: DisableNTLMPreAuth
Data Type: REG_DWORD
Value: 1

In addition to the registry key you also need to turn off Enable Integrated Windows Authentication in Internet Explorer. To do this, follow these steps:

  1. Start Internet Explorer.
  2. Click Tools, click Internet Options, and then click the Advanced tab.
  3. Under Security, click to de-select Enable Integrated Windows Authentication (requires restart), and then click Apply.
  4. Close Internet Explorer.

To resolve this issue from the server side, configure the Web site to use either of the following authentication methods:

  • Configure the Web site to permit anonymous access only.
  • Configure the Web site to permit both anonymous access and NLTM authentication (Integrated Windows authentication).

For more information, click the following article numbers to view the articles in the Microsoft Knowledge Base:

324274 How to configure IIS Web site authentication in Windows Server 2003

310344 How to configure IIS 5.0 Web site authentication in Windows 2000


Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

Additional query words: HTML, ASP ASP.NET

Keywords: kbnetwork kbprb KB251404