help with norton internet security 2011

Hello there, This is my first post and Im a very basic user so please dont use any big computer terms:smileywink: I bought a 2011 security from PC World to install on my computer and net book. (have used these before) Have installed on net book no problem but when I try the cd drive it freezes and I have to shut down. Dont know if its my computer or the disc but as I have already installed on netbook cant take it back. Is there anyway to just enter the product code somewhere? Have looked all through the site but cant find anything. Computer security expires in 3 days so HELP!!

Thanks Linda