My computer needs a new video card but it won't install!!?

I want to update my video card so i can play second life, but i only have a GDI Generic, and i need at least a GEForce 2 or an ATI Radeon 8500, i have downloaded everything i need to install these, but everytime i try to install it it says it doesnt have the nessesary software to finish it. My computer is an windows XP.|||You have to BUY a new video card, its hardware, not software...checkout the link i posted below for cheap graphic cards..but make sure you buy one thats compatible with your system.|||you cant just download geforce its a video card and geforce 2 cost 40 bucks|||You have to buy the new video card, open up your computer, take the old one out and install the new one.