Rather than clicking on the task bar and then safely removing the pendrive you can eaily do so creating a shortcut:THE STEPS ARE
1)Create shortcut on your desktop by right click and selecting new shortcut from the menu.
shortcut is created and now you can assign a shortcut key to it.
just right click on it and select properties-> click on shortcut tab -> assign a shortcut key to it(it will take clrt + alt by default)eg: if you press 1 shortcut will be ctrl+alt+1