You receive a "you are not authorized to view this page" error message when you try to access an external Web site that requires authentication through ISA Server, through Forefront Threat Management Gateway, or through Windows Essential Business Server
This article was previously published under Q284666
When you try to access an external Web site that requires authentication, you are not prompted to enter your account credentials. Therefore, you cannot access the Web site. When you try to access the Web site, you receive the following error message:
You are not authorized to view this page
This problem may occur when all the following conditions are true:
A version of Microsoft Internet Explorer that is earlier than version 6 is installed on your computer.
Internet Explorer is configured as a Web proxy client of a computer that is running Microsoft Internet Security and Acceleration (ISA) Server 2000, ISA Server 2004, ISA Server 2006, Microsoft Forefront Threat Management Gateway, Medium Business Edition, or Windows Essential Business Server 2008.
The external Web site is located on a computer that is running Microsoft Internet Information Services (IIS) that is configured to use Integrated Windows authentication.
Note In IIS 4.0, Integrated Windows authentication is known as NTLM or as Windows NT Challenge/Response authentication.
To resolve this problem, upgrade Internet Explorer to version 6 or later. Also, Microsoft recommends that you install the latest Internet Explorer updates from the Microsoft Windows Update Web site.
Microsoft has confirmed that this is a problem in Microsoft Internet Explorer.
To obtain the latest version of Internet Explorer and Internet Explorer updates, visit the following Microsoft Windows Update Web site: