Norton V6 Full System Scan Hangs

I've just upgraded to Norton V6 20.2.0.19, latest LiveUpdate level, on Windows 8, latest update level, from earlier V6 and Windows 7. Hard drive has 422GB in use. When I run full scan, after 16 hours it's sitting on Windows Sidebar, and an hour later, it's still there. It won't cancel or close. I have to restart system.

Help please.

Chuck