If your wires are connected turn in your cable modem. Then turn to the computer system that is connected to the cable modem. Then refresh the display, Following the browser opens onto your computer that's connected to the cable modem and see the site. This to register your modem, and follow all of the documentation on the registration page, brings your browser to the registration page. If the activation site doesn't open then visit xfinity.com/authorize to activate your modem. Follow all the instruction and provide your Comcast account number and phone number . However, if the page doesn't seem then delete the default/ current DNS server on your pc, then access Comcast activation page