You disable onboard graphics through the BIOS. When your system is booting you should see the motherboards splash screen and somewhere an indication like <Press Delete to Enter Setup>. Follow the screens to the area that disables onboard video. Your motherboard manual should explain how.
and life goes on...
Hey i recently installed a new graphics card jaton low profile 208pci mx 4000 anyways i leanred after reading the manual that i need to somehow disable my computers integrated video card or else the card wont work and it doesnt but how do i disable my computers video card ......I deleted the drivers in add and removed programs o ya also my card is a Intel R 82845G it SUCKS