I downloaded the Norton Security app and clicked on its offer to upgrade to the full version. It said I could not unless I have Android Market version 5 or higher. So I hit Settings, Apps, Android Market, and saw that my brand new Samsung Galaxy Nexus came with Android Market version 3.4.4. So, I have been struggling ever since to learn how to upgrade Android Market. Google technical support told me to open Android Market, switch to my Home screen, and wait 20 minutes for Android Market to upgrade itself. Didn't work. Somebody please solve this problem!