this page is the main support and download page for the ASUS A8V-X
motherboard ASUSTeK Computer Inc. -Support- Drivers and Download A8V-X
this is a link to the download page of Matrox (unfortunately, the url does not support direct linking, so you have to manually drill down and select the graphic card)Matrox Graphics - Support - Driver Download
in case you cannot find the driver, check the link for older/legacy Matrox drivers Matrox Graphics - Support - Latest Matrox drivers for legacy products
please remember that that type of windows serial keys are matched with the type of installer cd's. an installer cd for Enterprise does not always work with a serial number that is meant for personal use/OEM.
the simplest way should have been a purchase of the windows cd with the license booklet/cd case/cardboard case that contains the genuine sticker and license key.
====================== 32bit and 64bit reminder
remember to check the driver version that you are going to install. if you will be using a 64bit version of windows, your device drivers should also be the 64bit version.
goodluck on this, we hope you get it running and be put to use
***or you can try any of the free linux alternatives like Ubuntu/Xubuntu
xubuntu is based on Ubuntu, except that it was made for lower/older spec computers. (ubuntu.com or xubuntu.com)