Since I updated yesterday (Norton updater requested a restart) I have had 2 occasions where the Windows shell hung.
First indication was when Chrome browser (Version 56.0.2924.87) stopped loading pages. I couldn't close the Chrome browser and noticed that I could not launch anything from the task bar. The Start menu did not respond either. The windows button caused a message window to open telling me that the application was not responding (did not say which) and asking if I wanted to exit the program. I clicked yes, the message disappeared and nothing happened. The spinning wait cursor appeared over the chrome window and over the task bar. I waited about 1 minute and tried to close the program again. Still no joy. I repeated this a few more times assuming the more than one program was not responding. I still was not able to get a response from the Windows icon or Windows button. It forced me to use the power button to do a hard shutdown.
The system came back up without complaint but I doubt that I will tolerate much more of this. I am certainly willing to work with you to determine whether Norton Security is the issue and investigate what is happening.
I have installed no new software and the system was working fine up until yesterday around the time I got a notice the Norton updater wanted me to reboot my system.
Addendum: It occurs to me that the Windows Mail App was active at the time as well. It too was not behaving normally. I had to close it at one point because it wasn't syncing/opening the mail item for viewing.