Answer
Its impossible,laptop video cards are built into the mainboard(motherboard) this is because manufacturers need to save space to cram all the components into the limited space of a laptop cheaper laptops tend to use intergarted graphics,such as intel and s.i.s chipsets,but the more expensive laptops use better graphic chips i use the word"chips"and not cards as thats basically what they are,even the nvidia geforce 7800 adapters that would normally come in a massive card with fan and heatsink come as a small graphics chip in a laptop but still manage to produce the same graphic reproduction some manufacturers,like nvidia experimented with a technology called "mxm" graphic chips,(http://www.nvidia.com/page/mxm.html),this is the closest you will get to upgrading a laptops graphic chip,it basically is a slide in chip on a small board( similar to a memroy module)and you could in theory take out your current graphics chip and insert a more up to date and powerful chip this is still a rare upgrade as not many manufacturers of laptops like to include this in their laptops as it makes them expensive to manufacter,and like we all know ,we dont like paying thousands for a laptop my advice is when the lifespan of this laptop has ended,stick to normal desktops,they are easy to upgrade and can be tailored to any type of use,gaming,office,video editing ect to enhance your current graphics chip in your laptop try updating the display drivers(http://www.nvidia.com/content/drivers/drivers.asp)a.t.i(http://ati.amd.com/support/driver.html) and intel(http://downloadfinder.intel.com/scripts-df-external/support_intel.aspx) also download the latest direct x runtime files(http://www.microsoft.com/downlots/details.aspx?familyid=2da43d38-db71-4c1b-bc6a-9b6652cd92a3&displaylang=en),these will improve the 3d graphics sub-system on your laptop,thus improving the performance of your games i hope this has helped nice luck
