If you want more space on your desktop, then it is recommended that you should keep your taskbar on auto-hide. The Taskbar Hider is a free, light-weight and portable application which hides the Windows taskbar with a shortcut key, a great way if you want to hide the taskbar manually.
The working of this tool is very simple, it loads in the system tray and whenever you hit the shortcut key, it will hide/unhide the taskbar. Right-click the system tray icon and choose the Settings option to change the default shortcut keys.
It works on all modern versions of Windows, such as, Windows XP, Windows Vista, Windows 7 and Windows Server 2008. Enjoy!