How to get Norton product and subscription on new PC?

My PC recently died completely, couldn't even get to the main screen so have purchased a new one. I had installed Norton Internet Security/Anti Virus from a 2006 disc and have renewed my subscription online every year thereon. I have read other posts relating to this subject but not being very technically minded wondered if someone could tell me in simple terms how to get Norton on my new PC as I still have time left on my subscription.

Do I need to re-install the 2006 disc that I still have? Or do I just need to download everything off the internet? Sorry, I am totally confused and want to make sure I do things right and not leave myself open to any virus etc.

Any advice would be much appreciated.