If you have on board, then you dont need a video card.
Ok i am confused..What exactly is your question? DO you have onboard graphics? In your Profile it says that you have a video card..but then you talk about onboard graphics...i am lost.
I currently have onboard graphics myself (will be getting new card shortly) but i would disable or uninstall the onboard graphics and buy a card or find driver updates as was earlier posted. I am no expert but i am having small problems with mine so this is what i am doing. Do you have PCI or AGP card slots? Try some on the Radeon Products.