Windows Voice Greeting

This came my attention upon watching the movie ” Independance Day”. I have been asked by others as well in regards to my question. On the lap top of “Dave” he was “suppossedly greeted with a voice greeting. Now If this is an actuality does anyone know how this effect can be done. I would suspect that this would be best to occur after all programs and the desktop has finished loading. Any suggestions or help ? I would appreciate anything that can point me in the right diredtion