In Windows 7 the Taskbar Notification Area, or System Tray, displays a collection of items used for alerting and quickly adjusting basic system settings such as volume, network, battery power, computer issues, date and time. In this tutorial, we show you how to display and hide items that appear in the Notification Area.
Click the Show hidden icons button then click Customize.
This will open the Control Panel Notification Area Icons item. If you would like to change the behavior of an icon, simply click in the list box beside it and choose the desired behavior.
For example, if I want to have the Microsoft Encarta Dictionaries icon always displayed in the Notification Area, click in the list box beside it and click Show icon and notifications. See below.
If you want to hide a notification, repeat the same step, but choose Hide icon and notifications.
If you want to change the behavior for system icons displayed in the Notification Area such as Clock, Volume, Network, Power and Action Center, click the Turn system icons on or off link at the bottom of the window.
In the above example, I have changed the Taskbar Notification behavior to hide the Clock, see the before and after inset.