Installation of AGP Video Card…

I need help installing an NVIDA 128MB graphics card. Its AGP not PCI. After installing it to the motherboard, the cpu turns on, but the monitor stays off. What is the deal. My motherboard is a SOYO SY-P4VGM v1.0, I am using WIN XP pro, 512 MB RAM, 17? CRT. Origionally the graphics are controlled with onboard graphics..PRO SAVAGE DDR. How do I disable this to install the GForce? I tried uninstalling it and then plugging in the GForce, with the same results….Please help….