Right click on the Start button, select Properties, Taskbar tab, Notication area -Customise button. At the bottom of the page is "Always show all icon and notifications on the taskbar". Uncheck the box before this item. Further up the page is a built in
window with a scroll bar on the right. Use the scroll bar to check for a hidden Action Center. The selection for Action Center should be set to "Show icon and notifications". If a different option has been selected, change it and recheck the box before "Always
show all icon and notifications on the taskbar".
Now click on "Turn system icons on or off". Use the scroll bar on the right of the windows to see if Action Center has been hidden and check that it is turned On. If not On then turn it On and click on OK and Apply. Restart your Computer.
The Action Center flag can take a little time to appear in the tray, so do not immediately assume it has not worked if it is not there when the reboot has completed.