I found suggestions online to fix the missing icons, which directed me to Taskbar>Properties>Notification Area>Customize.
However, clicking on Customize gets an error message:
Going to my Control Panel>Default Programs>Set Associations, I get a long list of of Extentions, with Description and Current Default. However, I have NO CLUE what extention I need to touch, nor what Default to set if I knew the Extention!.MS-settings:notifications
This file does not have a program associated with it for performing this action. Please install a program or, if one is already installed, create an association in the Default Programs control panel.