Very Basic Question

For several years I have been running NIS on five different computers with five different email addresses.  I have always just bought an NIS 1user, 5 PCs package and used the product code to renew my subscription on each computer.  In 60 days I need to renew again and would like to take advantage of  the reduced price on Internet Security.  I have never bought directly from Norton and do not know how it works.  When I make the purchase from Norton, do they issue me a product code to use on my five computers?  I want to buy now, but accomplish the actual renewal 60 days from now.  I also hope that Norton has the "slow shutdown" problem solved by then.  Thank you for your knowledge.