Logon failure events are incorrectly recorded for trusted MIT Kerberos realm users

When users log on to their user accounts that are from a trusted MIT Kerberos realm, a logon failure event is incorrectly recorded in the security event log of the domain controller. Additionally, if an account lockout policy is enabled, these user accounts may become locked out. However, the users do not experience a logon failure when the lockout occurs.

This problem may occur if the Encrypting File System (EFS) is used to help protect files on the local computer. EFS relies on the Data Protection API (DPAPI) to encrypt a user's key by using a master key. Starting in Microsoft Windows XP, the DPAPI tries to back up this master key to the domain controller every time that the user changes the user logon password. Because a service principal name (SPN) is not correctly formed, authentication that uses an account from a trusted MIT Kerberos realm causes a logon failure on the domain controller.

Service pack information

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

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.

File information

The English version of this hotfix has the file attributes (or later) 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.

Microsoft Windows XP

Microsoft Windows XP 64-Bit Edition

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 Microsoft Windows XP Service Pack 2.

For additional information, click the following article number to view the article in the Microsoft Knowledge Base: