Use a desktop keyboard in case of emergency or for security purposes(Windows Vista, 7)

                Your wireless keyboard is not working as the batteries are unexpectedly empty. Still, it’s urgent: you quickly need a different method to enter text to finish an important document.

               While shutting down the computer is easiest with a mouse, it becomes considerably slower when entering text using a mouse. For emergency cases, Windows offers a seldom-used aid to carry out all processes using the mouse: the desktop keyboard.
                To activate it, you will have to activate the tablet PC input field. For that, right click a free area of the taskbar and select the command ‘Toolbar | Tablet PC input panel’. You will first see the additional writing pad symbol to the right in the taskbar, which superimposes the window for entering text or desktop keyboard after a click on it. Both modes can be switched over using the icons to the left in the title bar of this window. The input aid remains in the foreground and enables cursive writing using the mouse. The clicks are directly implemented as keystrokes in other open windows and applications. By closing the window, you can only minimize it wherein it is shifted to the left margin of the screen where you can always access it easily. Moreover, you will have to ‘Display extended keyboard’ via ‘Tools’ to get access to the scrolling control elements. You can close the tool completely only via the ‘Tools | End’ entry.
Note: The desktop keyboard is also useful for safe entry of passwords and the rejection of monitoring by keylogging tools, since no keyboard entries pass through a hardware interface.