Assign Hotkeys To Hide Or Show Windows XP/Vista/7 Taskbar Using Taskbar Hider
Windows users can hide their taskbar automatically so that the taskbar comes into visibility only when you hover your mouse at the edge of the screen. (This feature can be enabled by right-clicking on Taskbar, choosing Properties and selecting the option ‘Auto-hide the taskbar’ in the Taskbar tab.) However many users do not prefer this method of hiding taskbar as it requires them to hover and wait for the taskbar to come into picture.
Here is a small and free utility, Taskbar Hider, which allows you to hide/unhide taskbar with hotkeys. The application sits in the system tray when it is run, giving quick access to it’s settings window. By default the program uses WIN + X to toggle between hide and show modes for the taskbar. You can program custom keyboard shortcuts as per your needs.
Optionally you can choose to run the program at startup so that you don’t have to manually execute it each time. Taskbar Hider is a standalone application, so you can carry it anywhere you like in a USB flash drive.
By using Taskbar Hider, Windows 7 users can take maximum advantage of the newly added Taskbar shortcuts to cycle through taskbar icons and invoke applications. They can do everything related to the Taskbar through keyboard shortcuts.

Taskbar Hider works with Windows XP, Windows Vista, Windows 7.