Article ID: 923155
Important This article contains information about how to modify the registry. Make sure that you back up the registry before you modify it. Make sure that you know how to restore the registry if a problem occurs. For more information about how to back up, restore, and modify the registry, click the following article number to view the article in the Microsoft Knowledge Base:
(http://support.microsoft.com/kb/256986/ )Description of the Microsoft Windows registry
Consider the following scenario. On a Windows XP SP2-based computer, you use Microsoft Internet Explorer 6 to open a Web page. You try to use the POST method to post data to the Web server that hosts the Web page. In this scenario, you cannot post the data to the Web server. This problem occurs if the Web server uses the Kerberos version 5 authentication protocol to improve security.
Note This problem only occurs when you use the POST method for the first time. If you click the Back button to go back to the Web page, and then you post the data again, you can successfully post the data to the Web server.
This problem occurs because of a defect in the WinINet.dll file. When you try to post data to the Web server in Internet Explorer 6, the WinINet.dll file obtains new credentials, and then the WinINet.dll file frees the original security context. Then, the WinINet.dll file calls the InitializeSecurityContext function to initiate the outgoing client-side security context.
In this scenario, the WinINet.dll file will not check whether the authentication scheme of the Web server is NTLM authentication or Kerberos authentication. Because of the defect, the WinINet.dll file expects that the Web server uses the NTLM authentication scheme. Therefore, the authentication fails, and you cannot post data to the Web server.
Hotfix informationA 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:
PrerequisitesTo apply the hotfix, Windows XP Service Pack 2 (SP2) must be installed on the computer.
Restart requirementYou have to restart the computer after you apply this hotfix.
Hotfix replacement informationThis hotfix does not replace any other previously released hotfixes.
Registry informationWarning 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 the operating system. Microsoft cannot guarantee that these problems can be solved. Modify the registry at your own risk.
To enable the hotfix, follow these steps:
File informationThe 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 item in Control Panel.
Windows XP with SP2, x86-based versions
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Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
For more information about the InitializeSecurityContext function, visit the following Microsoft Web site:
http://msdn2.microsoft.com/en-us/library/aa375506.aspxFor more information, click the following article number to view the article in the Microsoft Knowledge Base:
(http://support.microsoft.com/kb/824684/ )Description of the standard terminology that is used to describe Microsoft software updates