How to Hide the Taskbar in Windows 7
The taskbar in Windows 7 is a complete redesign from Windows Vista and Windows XP. In the redesign, some of the features remained from Windows XP and Windows Vista. One such feature is the ability to hide the taskbar to maximize the real estate on your computer screen. This functionality allows you have the benefit of using your entire screen as well the Start menu when you move the mouse to its location.
Right-click on empty space on your taskbar and choose "Properties."
Click the "Taskbar" tab. Your computer should automatically default to this tab.
Select the "Auto-hide the taskbar" checkbox.
Click "OK." The taskbar disappears and only reappears when you move the mouse to its location.