Error message when you try to access a Web site in Internet Explorer 7: "Page cannot be found"

When you try to access a Web site, you may receive the following error message in Windows Internet Explorer 7: If you click Refresh, the Web page may open successfully. This problem occurs if the following conditions are true:

• The Internet Security and Acceleration (ISA) Server and the server running Internet Information Services (IIS) server are configured on the same computer.
• The ISA server is configured for content filtering and sends a redirect request back to the client to visit the server running IIS.
• The Content-Location header in the ISA server is configured to reference the IP address of the server running IIS instead of the Qualified Domain Name Service (DNS) or the NETBIOS name.

This problem occurs because the redirect that the content filter generates sends a redirect to the client. Internet Explorer adds the IP address and the port value to the internal proxy result cache by mistake, and then Internet Explorer sends the requests directly to the Web server.

To resolve this problem, use one of the following methods:

• Modify the redirect request to use a NETBIOS or qualified DNS name instead of the IP address.
• Move the server running IIS to a different computer.
• Disable automatic proxy caching in Internet Explorer.

For more information about how to disable automatic proxy caching in Internet Explorer, click the following article number to view the article in the Microsoft Knowledge Base: