I have had it with these norton chat techs. In fact some of them are stupid. Some would remove two lines in the registry and claim the problem was permanently fixed. One of the later techs didn't even touch the registry. He just restarted explorer.exe and said it was fixed. I didn't know whether to laugh or say a few choice words. So I put together a reg fix script that I can click on to remove the extra icon. Sure beats putting up with norton chat techs.
I did encounter the really slow booting each time it would have two norton icons. I put up with it for a while. I ran across something that might be worth looking into by someone that knows the windows updates. About two months ago I got some automatic updates to windows 8.1. The computer came to a crawl in booting and operating. In frustration I removed a large number of updates from windows 8.1 security updates. I got my boot up speed back up to impressive now and I have yet to see two norton icons in the taskbar. I stopped all automatic windows 8.1 updates. It might not be the ideal fix but the results were great in boot speeds and stopping the two norton icons in the taskbar.