To delete Norton Internet security from your computer is by uninstalling it from the Add or Remove programs. Just click on the Start menu and go to Control Panel. From the Control Panel, select Add or Remove Programs and then select Norton Internet security from the list to uninstall.
Vincent and crow gave good answers, but if there is an option in the program to uninstall it that is a good method too. I would like to point out that Microsoft offers antivirus protection free of charge. The program is Microsoft Security Essentials.