gstatic

Connect it to the coax line and power it up. Let it fully sync up with the system, and check that the front / top panel indicator light(s) are steadily lit. 

Then connect a computer to it and open up a browser. You *may* see their *Walled Garden* modem self-registration page. If so, follow the screen prompts. Have your mobile telephone number, your Xfinity username and password, or the account number and telephone number associated with your Comcast account handy.

If not, try calling 1-855-652-3446. That is their self-install device activation line.

If that doesn't work for you, you can call 1-800-comcast and tell a rep that you would like to have a new modem provisioned for service. Have the RF / CM / HFC MAC address and the serial number of it handy when you call.

@santafosb2 Hello! Thank you for reaching out to us here on our Community Forums page. It looks like Gstatic is some type of Google extension. If you need any assistance installing your new modem/router we'll be happy to help you with that. We may need you to send us a Private Message with your full name and address to assist you with installing your new modem. Here are some instructions on how to send us a PM in case you need them:

Click "Sign In" if necessary
 • Click the "Peer to peer chat" icon (upper right corner of this page)
 • Click the "New message" (pencil and paper) icon
 • Type "Xfinity Support" in the to line and select "Xfinity Support" from the drop-down list
 • Type your message in the text area near the bottom of the window
 • Press Enter to send your message

We look forward to speaking to you there. 

@santafosb2 

Did any of those methods work for you ?