You'll need to turn the pc off, remove the cover and install you graphics card (whilst taking anti-static precautions) turn your pc back on whilst tapping F1 to enter the bios. Using the arrow keys navigate to the 'advanced' screen and select the 'primary video adaptor' option. Change this from 'pci' to 'vga'. Press f10 and select yes to save changes. Reboot, install the drivers that came on the cd when windows loads.