Even if it's possible you probably don't want to do that. Too expensive and too much trouble to replace IMHO.
probably better off getting another laptop or a tablet if you want touch.
thanks. your probably right was only interested as i work as a dj at weekends and use my laptop for it. A touch screen would be handy. this ole laptop has served me well and is reliable but i should put the money together for a touch screen laptop in the future