Can't activate new Xfinity Internet

We set up our new Internet Essentials service hours ago but can't get it to activate.   We tried both wi-fi and ethernet connections, and have also reset the modem multiple times.   When we try to activate, we get a pop-up window on our laptops called "XFINITY Smart Internet" at http://10.0.0.1/captiveportal.php, but at most we get a blue screen that won't finish loading.   When I reset the modem through Comcast, I get a message saying there are no connection issues, and to make sure the devices are connection to the home network, which they are.  However the status center says they're having trouble finding a signal.