There seems to be a big long thread here, but it's hard for me to find a real explanation or solution:
https://answers.micr...-e49f344095e5?auth=1-mouser (May 22, 2017, 02:26 PM)
I've found a solution by StephenHaxby in this thread:
Notification settings are saved in an SQLite Database here:
You can view the contents with any SQLite Database reader/query, I used this:
Just search the 'NotificationHandler' table for the notification you want to delete (select * from NotificationHandler), in my case it was 'Symantec.ToastUI' and it was at 'RecordId' 72.
Then just delete everything conected to this Handler:
delete from HandlerSettings where HandlerID = 72
delete from Notification where HandlerId = 72
delete from WNSPushChannel where HandlerId = 72
delete from NotificationHandler where RecordId = 72
Save the DB (if you are using the app above) and re-open the Notifications Settings App.
Your unwanted/uninstalled app should now be gone.
Well... It was for me...
As said may times in this thread, you should be deleting registry entries...