Whether you've installed a copy of Norton Internet Security on your computer, or your pre-installed Norton Internet Security software's trial has expired, it is important to activate your product in order to continue using the software. According to the official Symantec website, a Norton product that is not activated is restricted from use, which leaves your computer open to attacks as it is no longer protected by the program. Activation of your Norton software requires a credit or debit card, as well as an active Internet connection that allows the program to connect to the Symantec server.
Click the Start menu button, click "All Programs" in the pop-up menu and select "Norton Internet Security" to run the program.
Click the "Activate Now" button that appears at the bottom of the Norton Internet Security's program window, or click "Renew Now" if you're using pre-installed software. Click "Next" in the Norton Account window, and enter your full name, address, phone number and e-mail address. Click "Next" to proceed with the activation.
Type in the Norton product key located on the software's product case or select your payment method, and enter your 16-digit credit card or debit card number. Enter your expiration date, and enter the security code located on the back of your credit or debit card.
Click "Next" and wait for the Norton Internet Security program to connect to the Symantec server. The program will send your billing and payment information to the Symantec server, and activate your program.