The notification area is in the lower-right corner of the screen, located at the far right of the taskbar. It contains program icons that provide status and notifications about things like incoming e?mail, updates, and network connectivity.

For help on how to change which icons show in the notification area, please see this handy article on the Microsoft web site:
http://windows.microsoft.com/en-us/windows7/change-how-icons-appear-in-the-notification-area
There is a video that shows how to change which icons appear in the notification area.