Loading a 2nd NIS 2011 to extend the expiration date.

My currently installed NIS 2011 expires this Oct. Recently, I purchased a 2nd NIS 2011 (3 computer version) to load on our laptops. Now, I want to take advantage of the new expiration date of July 2012 by downloading NIS 2011 to my PC (the 3rd and final version available), but when I click on the download button next to my order (Norton Online Store) it quickly installs the NIS installer, but then nothing happens. Any help would be appreciated.