I have Comcast xfinity . I disconnect my old modem , connect this modem , and then `` re-plugged '' my wireless router . a Comcast installation screen appear on my laptop when I open Explorer . you need you Comcast account number -lrb- on you bill -rrb- , I follow the step , and it work great . I do not need they , but I be keep the number on the bottom of the box .