Error message when you log on to a Windows Vista-based or Windows Server 2008-based computer that has the "Allow user name hint" Group Policy setting enabled: "The specified username is invalid"

Consider the following scenario:

• In an Active Directory Domain Services (AD DS) environment, you apply the Allow user name hint Group Policy setting to the Windows Vista-based or Windows Server 2008-based client computers. This Group Policy setting displays the domain name when a user enters the user name.
• A user uses a Smart Card certificate for authentication during logon.
• The Smart Card certificate has a subject name that is presented in the fully distinguished name (also known as DN) format. Additionally, the domain component of the subject name does not match the domain in the network.

In this scenario, when the user tries to join the domain from a Windows Vista-based or Windows Server 2008-based client computer by using the Smart Card certificate, the user cannot join the domain. This problem occurs even though the name of the domain that the user tries to join is presented by the hint. In this case, the user receives the following error message:

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.

Important Windows Vista and Windows Server 2008 hotfixes are included in the same packages. However, only one of these products may be listed on the �Hotfix Request� page. To request the hotfix package that applies to both Windows Vista and Windows Server 2008, just select the product that is listed on the page.

Prerequisites

To apply this hotfix, you must have Windows Vista Service Pack 1 or Windows Server 2008 installed on the computer.

Restart requirement

You have to restart the computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace any other previously released hotfixes.

Registry information

To use this hotfix, you do not have to make any changes to the registry.

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 item in Control Panel.

Windows Vista and Windows Server 2008 file information note

The .manifest files and the .mum files that are installed in each environment are listed separately in the "Additional file information for Windows Server 2008 and for Windows Vista" section. These files and their associated .cat (security catalog) files are critical to maintaining the state of the updated component. The .cat files are signed with a Microsoft digital signature. The attributes of these security files are not listed.

For all supported 32-bit versions of Windows Server 2008 and of Windows Vista

For all supported 64-bit versions of Windows Server 2008 and of Windows Vista

For all supported Itanium-based versions of Windows Server 2008

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 subject name, visit the following Microsoft Web site:To enable the Allow user name hint Group Policy setting, follow these steps:

1. Locate the Group Policy object (GPO) to which you want to apply this setting.
2. Expand Computer Configuration, expand Administrative Templates, and then expand Smart Card.
3. Double-click Allow user name hint, click Enabled, and then click OK.

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

Additional file information for Windows Server 2008 and for Windows Vista

Additional files for all supported 32-bit versions of Windows Server 2008 and of Windows Vista

Additional files for all supported 64-bit versions of Windows Server 2008 and of Windows Vista

Additional files for all supported Itanium-based versions of Windows Server 2008