Upgrade graphics toshiba c640

just by looking at the specs it does not mention that you are able to upgrade the GPU. the laptop has an intel HD 3000 GPU so the 2 possibilities. the GPU may be integrated on the CPU itself so you would have to upgrade the CPU because there is not a separate socket for the GPU(assuming it is not soldered onto the board). the other possibility is that only intel GPU's would work with it and no mdel of intel GPU's are good for gaming

but the option i am giving depend on how skilful you are with computers. it is easy to take a laptop apart but the challenge is getting it back together
 
The c640 came in a variety of specs some had dedicated graphics so it may or may not be impossible to upgrade but since you cannot buy a laptop graphics card at a reasonable price (if at all) and even if you got one its a total nightmare to fit and even if you get round all this you may need a bios update you can't get. Basically laptop graphics cards are frequently just not upgradeable and when they are you can't buy them anywhere and they are a nightmare to install. Unless you are an expert forget about it.