The easiest way to download the drivers for your system is to buy them using a diagonsic application. For this instance, CPU-Z is more than enough. Download the application and run it. Click on the Motherboard tab and note the motherboard name, then paste the information on Google and usually the first website that appears is the manufacturer's one. Click on the Downloads tab on the website and you will get the possibility to download the driver for your graphics card. If you have an external graphics card, select the Graphics tab and then do the same.