A. XP uses the standard HTTP port (port 80) and HTTPS port (port 443) for product activation. To confirm that these ports are available, try connecting to both ports by entering the following addresses in your Web browser:

  • http://www.microsoft.com:80
  • https://www.microsoft.com:443

If you receive an error, check with your administrator to determine whether your organization has blocked either port and whether you need to change your firewall client configuration.