Each year when the new version of NIS is available and only if you still have time left on your subscription you can upgrade for free.
Log into your account look for upgrades for present customers, select NIS 2011 for example as your current ver. and then 2012 will be installed on your pc. Just remember to buy 2012 ver. next year and type in your new key number. It helps if you can delay your NIS install each year giving you four or five months on the new ver. not the beta. Plus when you wait till later in the new year you can save a lot on your new purchase. This has worked for years for me, hope it helps.