You may not realize that Windows XP comes with a rather cool virtual keyboard that you can operate with your mouse. When you start the On-Screen Keyboard a graphical representation of a keyboard is loaded as a separate window.
To type with the virtual keyboard, you simply click the corresponding key with your mouse. This feature is mainly intended as an accessibility option. The On-Screen Keyboard allows people with mobility impairments to type using a mouse or joystick in place of a standard keyboard. It might also come in handy as a temporary workaround if your normal keyboard goes haywire.
To access the On-Screen Keyboard:
1. Open the document that you want to type into.
2. Hit Windows Key + R to open Run (Or click “Start /Run”)
3. Input "OSK" (without the quotes) in the Run box and hit enter.
4. The virtual keyboard should load.
Even if you never have a legitimate need to use the On-Screen Keyboard, its good to know its there. Besides, my children like playing with it (grin).
Microsoft Article - Using On–Screen Keyboard