You would go to the maker of the mother board and find the model of your mother board on their support/download page and it should have whatever available drivers were made for the board. Beyond that if a later OS supports those boards the correct chipset driver will already come with Windows.
not that, I want to download the Chipset drivers, like the a75, and on the download page they simply do not appear, only have the am3 / am3+ and am4 / tr4 platform chipsets
