If you are sure that you have entered the code correctly and you still see an error message, the problem may be that PhotoModeler cannot reach the activation server. You may be using a proxy server or have a firewall (Windows XP/Vista firewall, ZoneAlarm, BitDefender, etc.). Make sure you have given permission for PhotoModeler to access the Internet in your firewall or if you are using a proxy server ensure that the proxy server settings are correct in the activation dialog (see Proxy Settings).