To register a new modem with Comcast, you will need to hook up the modem to your Comcast Internet service. If you have a third-party cable modem, Comcast advises you to follow the instructions that came with the modem. Any third-party modem must be Data Over Cable Service Interface Specifications-, or DOCSIS-compliant.
Connect your coaxial cable from your cable outlet to your cable modem. Accomplish this by screwing the ends of the coaxial cable into the cable wall outlet and the cable connection on your modem.
Plug in either your USB cable or your Ethernet cable. If you prefer to use USB, plug your USB cable into the back of your modem first, using the small square end where you find a "USB" labeled port. Subsequently connect the flat end of the cable to a USB port on your computer. Plug your modem into a wall outlet by using the electrical adapter that comes with the modem. If using USB, your computer will automatically pick up your modem and install the hardware. Your modem lights will blink on and off in a series of patterns and register with Comcast. At this point, proceed to Step 4.
If you prefer to use Ethernet, plug the cord into the back of your modem and plug the other end into an Ethernet port on the back of your computer. Plug your modem into an electrical outlet on your power strip with the electrical adapter that comes with your modem and proceed to Step 3.
Put the installation CD that arrived with your modem into your CD/DVD-ROM drive. The set-up menu will load. Follow the instructions to install the modem on your computer. Once installation completes, restart your computer as prompted. When you computer reboots, the modem will connect and register with Comcast. Go to the next step before attempting the surf the Internet.
Open a web browser and follow the instructions on your screen to download and install the required Comcast software. Make sure you answer all questions during the installation process, agree to the "Comcast Residential Agreement" and accept the licensing terms when prompted.
Choose a user name as prompted, used for both Comcast email and accessing the Comcast website. Using the user name and your chosen password, log into the Comcast website as prompted. Download all other required software once you log into the website. Comcast will automatically check your computer and recommend required software to download and install. Follow the on-screen instructions for each prompt to accomplish this. Once complete, you can surf the Internet with your new modem.
Things You'll Need
Active cable Internet account with Comcast
Ethernet cable or USB cable
If your modem has trouble connecting to the Internet, you should recycle the modem. Do this by turning of the modem, unplugging it for two-minutes, then plugging it back in and turning on your modem. The modem will take about five minutes to recycle.
If you still have problems, you will need to contact Comcast for assistance at 800-COMCAST and request to speak with a technical support representative for high-speed cable Internet access.