How do I restore the Safely Remove Hardware icon?

This icon is hidden in Windows 7 but you can make it show in the notification area. This is very easy to do, but before you start, you need to insert a flash drive to trigger the icon's presence in order to modify it.

To launch the Notifications Area Icons dialogue box, click on your taskbar and choose "Customize" from the popup menu.

Scroll through the icons and find the labelled "Windows Explorer - Safely Remove Hardware and Eject Media". Now choose one of the three options from the dropdown menu on the right.

If you want to see all the icons all the time, tick on the box labelled "Always show all icons and notifications on the taskbar".