I installed the Norton Antivirus 2013 for my Windows 8 about 3 months ago, now it has 276 days left. Yet, I also just installed the same Norton Antivirus for another laptop just a week ago. Why do they have the same amount of days left of 276? Back then, when I had the Norton Antivirus 2010 version, the expiration of each computer started out differently. It only began when I actually install the system on it