Can you change your video card in a laptop thats a 17 inch if you already have one you just want to upgrade?

Alright so i got an Inspiron 17 with 4gb ddr3, an i5 prossesor, and a 512 ATI mobility Radeon HD video card. i know my card is weak and i was just wondering if i could upgrade my video card to a nicer one preferably with 1gb later on? or do i need to bring it to a local computer store?|||The graphic card in laptops is soldered to the motherboard during the manufacturing phase. It makes it virtually impossible to upgrade the graphic card in a laptop.