I want to upgrade my laptop's graphics card....

I am a laptop technician so I know your issue. In your situation with Compaq 6710b you can not upgrade graphic card because this series of Compaq 6710b is only support onboard VGA. As normally, upgrading graphic card in laptop is very rare company support to upgrade like Dell in some models (ex: Dell 640M). All the others not support to do that. So if your laptop is not enough good for onboard VGA, perhaps you should buy another with more stronger VGA.

yes,you can but i think it will costly cause laptop graphics card usually on board and if you upgrade it maybe you will need new motherboard ,BIOS and new driver too or it will conflict between motherboard and your new graphic card,it will be better if you buy new laptop with graphics card you want.