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Para desbloquear a barra de tarefas: Clique com o botão direito do mouse na barra de tarefas e desmarque a opção "Bloquear a barra de tarefas"
Unlock the Windows Vista Taskbar.
Move the pointer on top of the dots displayed between the Quick Launch icons. The arrow will change to a double-arrow.
Click with your left mouse button and keep the button held down. Now, move your mouse to the right to increase the size provided to the Quick Launch toolbar, or to the left to decrease it.