After upgrading my system from Windows 7 Professional to Windows 8 Pro, I could not run Quick Scan. The Quick Scan would show it's start screen but, nothing would happen. Additionaly, I could not shut NIS down manually or with or with Task Manager nor could I Restart System.
I was forced to power off system and restart. Next, I uninstalled Norton Internet Security, restarted system, reinstalled Norton Internet Security ensuring I had the latest version which is currently 20.2.0.19. At that point I was able to run Quick Scan OK. As it turns out, Quick Scan will not always start. I can click on Quick Scan and nothing happens, no start screen. If I close NIS, reboot my system and try to run Quick Scan again, it will work.
Note, before the upgrade to Windows 8, I have not had any issues with NIS. Thought I would share this to see if others have had similar experiences.
All the best!