Just a word to tell the community that I just upgraded my NIS [with 585 days remaining on its license] to Norton Security with backup with ease. It couldn't have been any smoother. A young lady named Amy assisted me on Chat and did the entire operation for me -- took the purchase, provided me with key, and transferred the days over for a total of 951. I told her my situation & concerns and she took over and did the rest. 5 minutes.
I told her about the horror stories out there ... I don't know if my experience is typical or not, but it was easy and the product, so far, is good! 10 devices, by the way, can be protected by the one license.
Just thought I'd pass my experience on to you all -- no, I am not a paid flunky. ;-)
Program is now installed on 2 PCs, so far ... one Windows 7, one Windows 8.1. Installation is easy, all settings are saved, and systems are good to go. Haven't set up the back up yet. IS Vault, btw, is all set to go, as well.
If you want to upgrade, don't be afraid. Norton has fulfilled their end of the bargain as far as I'm concerned.