Compaq Presario A931NR notebook, Video card upgrade?

I have a laptop but i'm not sure if i can upgrade it with a new video card or not?|||well some laptops you cant upgrade any of the hardware in it but if you take it to a computer shop and ask them if it is possible to open the case and upgrade but laptops are normally set when you buy the box and cant be upgraded but you never really know you could depending where you take it and how much are you willing to pay to get it done |||unfornatly it is dificult if not iimpossible to do that becuaSE the case is not expandible