When you attempt to access a Web site running IIS version 5.1 that is hosted on Windows XP SP2, you receive:

The page cannot be displayed. Can't find server or DNS error.

Windows XP SP2 enables the Windows Firewall by default, with port 80 blocked. This causes incoming HTTP protocol traffic to be blocked.

To resolve this issue:

1. On the Windows XP SP2 computer, Start / Run / firewall.cpl / OK.

02. Select the Exceptions tab.

03. Press Add Port.

04. In the Name box, type HTTP.

05. In the Port box, type 80.

06. Press OK.

07. If you need the HTTPS protocol unblocked, repeat steps 03 through 06, but use HTTPS in the Name box and 443 in the Port box.