NIS2013 replacement

 As my name implies, I've become confused.  I bought a new PC and removed the installed security software.  I then went to norton.com/nis2012 and tried to download a copy of NIS2012.  Somehow I ended up getting a trial copy of NIS2013.  I uninstalled the trial and went into My Account App and logged into Norton Management.  I clicked on the install tab and it installed the full version of NIS2013.  Do I need to uninstall NIS2013, run the NRT, then download and install NIS2012?  From where?