Are you able to see the wireless network in range when you look at your connections? What type of laptop is it that you are working with? Cause any of them should have a wireless switch/button to get the wireless card enabled/disabled. Is the comcast router an all in one device or seperate?
Oh and I don't think there's a home network group anymore, just regular old internet and they should t/s this for their customers now that they are handing out the router to anyone who rents a modem.