A Web form does not submit a user name and a password to a Web server in Internet Explorer 6

Consider the following scenario:

• The Web server uses the HTTP Negotiate Authorization header to authenticate clients on a Web site.
• You use Microsoft Internet Explorer 6 to access this Web site from a client computer.
• You are prompted to enter the user name and the password.
• After you enter the user name and the password and then click OK, you receive a Forms Based Authentication HTML page that includes a Web form. This Web form contains a user name field and a password field. The Web page also includes a message that states that the Web server denies NTLM authentication.
• You enter the user name and the password in the Web form, and then submit the Web form.

In this scenario, the Web form does not submit the user name and the password to the Web server.

This problem occurs because the Wininet.dll file prevents the data from being sent when the client uses NTLM authentication, and the Web server expects a Simple and Protected GSSAPI Negotiation Mechanism (SPNEGO) response.

When you submit the user name and password for the first time, the Wininet.dll file on the client computer adds an NTLM response to the Negotiate Authorization header. If the Web server expects an SPNEGO response, the Web server may send a response that is not "401 Access Denied." Because the response is not "401 Access Denied," Wininet.dll incorrectly assumes that the authentication was successful. When Wininet.dll assumes that a successful authentication has occured, Wininet.dll removes the authentication data that it saved and does not resend the data.

Windows XP

Hotfix information

A supported hotfix is available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing this specific problem. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next software update that contains this hotfix.

If the hotfix is available for download, there is a "Hotfix download available" section at the top of this Knowledge Base article. If this section does not appear, contact Microsoft Customer Service and Support to obtain the hotfix.

Note If additional issues occur or if any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. For a complete list of Microsoft Customer Service and Support telephone numbers or to create a separate service request, visit the following Microsoft Web site: Note The "Hotfix download available" form displays the languages for which the hotfix is available. If you do not see your language, it is because a hotfix is not available for that language.

Prerequisites

To apply this hotfix, you must have Windows XP Service Pack 1 (SP1) or Windows XP Service Pack 2 (SP2) installed.

Restart requirement

You must restart the computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace any other hotfixes.

File information

The English version of this hotfix has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time tool in Control Panel.

Windows Server 2003

Service pack information

To resolve this problem, obtain the latest service pack for Windows Server 2003. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

Hotfix information

Prerequisites

No prerequisites are required.

Restart requirement

You must restart the computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace any other hotfixes.

File information

The English version of this hotfix has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time tool in Control Panel.

Hotfix installation instructions

Warning Serious problems might occur if you modify the registry incorrectly by using Registry Editor or by using another method. These problems might require that you reinstall your operating system. Microsoft cannot guarantee that these problems can be solved. Modify the registry at your own risk.

After you apply this hotfix, enable the hotfix by adding two registry entries in the registry. To add these registry entries, follow these steps:

1. Click Start, click Run, type regedit, and then click OK.
2. To activate this hotfix on a per-user basis, click one of the following registry subkeys:
   • HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main\FeatureControl\FEATURE_HTTP_DISABLE_NTLM_PREAUTH_IF_ABORTED_KB902409
   • HKEY_CURRENT_USER\Software\Policies\Internet Explorer\Main\FeatureControl\FEATURE_HTTP_DISABLE_NTLM_PREAUTH_IF_ABORTED_KB902409
   Note You only have to add the registry entries to one of these registry subkeys.
   
   To activate this hotfix on a per-machine basis, click one of the following registry subkeys:
   • HKEY_LOCAL_MACHINE\Software\Microsoft\Internet Explorer\Main\FeatureControl\FEATURE_HTTP_DISABLE_NTLM_PREAUTH_IF_ABORTED_KB902409
   • HKEY_LOCAL_MACHINE\Software\Policies\Internet Explorer\Main\FeatureControl\FEATURE_HTTP_DISABLE_NTLM_PREAUTH_IF_ABORTED_KB902409
   Note You only have to add the registry entries to one of these registry subkeys.
3. On the Edit menu, point to New, and then click Key.
4. Type
   FEATURE_HTTP_DISABLE_NTLM_PREAUTH_IF_ABORTED_KB902409
   , and then press ENTER.
5. Click FEATURE_HTTP_DISABLE_NTLM_PREAUTH_IF_ABORTED_KB902409.
6. On the Edit menu, point to New, and then click DWORD Value.
7. Type Iexplore.exe to name the new DWORD value, and then press ENTER.
8. Double-click Iexplore.exe, type 1 in the Value data box, and then click OK to enable the hotfix.
   
   Note To disable the hotfix, type 0 in the Value data box.
9. To add the Explorer.exe registry entry, repeat steps 3 through 5. In step 4, type Explorer.exe instead of Iexplore.exe.
10. Quit Registry Editor.

To work around this problem, configure the Web server to support NTLM authentication. To obtain more information about how to configure the Web server to perform NTLM authentication, contact the vendor of the Web server.

For information about your hardware manufacturer, visit the following Web site:

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section. This problem was first corrected in Windows Server 2003 Service Pack 2.

For more information about the terminology that is used in this article, click the following article number to view the article in the Microsoft Knowledge Base: