) The irony is that although Microsoft claims Defender is better than MSE, Defender's GUI feedback is noticeably Microsoft is acting as if it's embarrassed about Defender and wants to hide any appearance that the program is present & working. When I'm doing a scan with Defender nothing appears in the Action Center to let me know what's going on, etc. Had to hack one into the shell to mimic that same functionality in MSE. Win8 Defender doesn't provide that, either-I Got feedback when you were doing a scan through the same icon, and in the right-click context file menu you were provided with an option to scan each file or directory or drive, etc., that you might select. With MSE you got feedback in the systray icon apart from merely letting you know the program was resident and actually monitoring your system-you OK, well, then what he's talking about is some kind of 'notification' as to the operational status of Defender. Otherwise, your machine is running fine (at least If there's a problem, you will get notified via this area.
It's Microsoft finally following its own guidelines for the notification area.
It is not the 'System Tray', it's the 'Notification Area'.