Restarting Computer After Full System Scan

I just recently in July got the newest version of Norton (22.5.2.15) . The full system scan seems to take a lot longer than the older version I had. Should it take longer?. Also ever since I got the newest version, I need to restart my computer to get on the internet or it is very slow getting on the computer after the full system scan. I don't get a message to restart the computer, but I did read that I might need to restart my computer after the full scan (this was read on the ? part of full system scan--that describes full system scan).

Holly

Windows Vista Home Premium

IE9 and Google Chrome (44.0.2403.130m)