Q. Why can't clients view a Web site that I'm hosting on a system that has Windows XP Service Pack 2 (SP2) installed?

A. XP SP2 includes the new Windows Firewall, which blocks inbound requests to port 80 (HTTP) and is enabled by default. To let clients access an XP SP2 Web host, perform these steps on the XP SP2 host:

1. Run firewall.cpl (Start, Run, firewall.cpl) to configure the firewall.
2. Select the Exceptions tab.
3. Click Add Port.
4. Enter HTTP for the name and 80 for the port.
5. Click OK.

If the XP SP2 Web host also serves HTTP Secure (HTTPS) Web pages, repeat these steps and enter HTTPS for the name and 443 for the port.