Error: 'HTTP Error 401.1 - Unauthorized: 'Access is denied due to invalid credentials' (NETIQKB54150)

Error: 'HTTP Error 401.1 - Unauthorized: 'Access is denied due to invalid credentials' error message when you try to access a Web site that is part of an IIS 6.0 application pool.'
Cannot log on to the console.
When accessing a Microsoft Internet Information Services (IIS) 6.0 Web site that is configured to use Integrated Windows authentication only, you are prompted for your user credentials. When you try to log on, you receive the logon prompt again. After you try to log on three times, you receive the following error message: HTTP Error 401.1 - Unauthorized: Access is denied due to invalid credentials.

This issue in IIS 6.0 has been identified and corrected by Microsoft Corporation.  For more information, see the Microsoft Knowledge Base article: 871179: http://support.microsoft.com/kb/871179.

This behavior occurs when:

• The IIS 6.0 Web site is part of an IIS application pool.
• The application pool is running under a local account or under a domain user account.
• The Web site is configured to use Integrated Windows authentication only.

Formerly known as NETIQKB54150