How to Activate Comcast Xfinity Cable Modem After Installation

How to Activate Comcast Xfinity Cable Modem After Installation

How to Activate Comcast Cable Modem After Installation. If you just bought a new Comcast modem and you installed it yourself or that someone who doesn’t really know much about how to provision Comcast cable modem did the installation for you, here is to successfully activate your Comcast modem with ease.

When you connect a cable modem to your CATV service line, the modem requests an uplink with the provider. The modem announces its identification through the MAC address, and the provider’s server confirms if your modem has authorization.

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The process of activating a Comcast modem to authorize it on a network is called provisioning. Whether you’re replacing an existing modem or establishing new service, the modem you are using must be provisioned on the Comcast servers

How to Activate Comcast Cable Modem

  1. Activate your modem by establishing a direct connection to your computer.
  2. Turn off your computer after saving any open files.
  3. Set your new Comcast cable modem near your computer and run a coaxial cable from a splitter or wall plate to the back of the modem.
  4. Ensure the connection to the back of your modem is hand-tight.
  5. Run an Ethernet cable between the back of your computer and modem.
  6. Plug in the modem’s power and turn on your computer.

Open a Web browser. This should automatically take you to the activation screen. If it does not, copy and paste “” into the browser’s address bar and press “Enter.”

Follow the on-screen prompts in the automated utility to activate your modem and agree to the Comcast Agreement for Residential Services license agreement.

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Comcast Xfinity Modem Activate Online

If the above steps on how to activate a Comcast modem didn’t work, you will need to follow the steps below to activate your Comcast Modem online.

  • Open a web browser. You should automatically be directed to the Xfinity Activation page. If not, please go to
  • Click Let’s Get Started on the first page, and then choose your preferred method of authentication.
  • Verify Your Xfinity Account. First, confirm one of the following details associated with your account:

How to Activate Comcast Cable Modem After Installation

  • Choose either of the following and click on the “Next” button
    • Mobile phone number
    • Xfinity Username & Password
  • After entering the appropriate information, activation will begin and you will receive notification when it has been completed.
  • To verify that your Comcast modem device has been activated, open a new web browser and go to a website to confirm you are able to surf.
  • Get instructions on how to return a modem you leased from Comcast.

If you have any further question even after you have followed the guideline above on how to Activate Comcast Cable Modem After Installation, use the comment section to reach us.