Hello,
I am running a Gigabyte Ati 6870 Windforce 3OC on Windows 7- 64bit. > this one http://www.gigabyte.eu/products/product-page.aspx?pid=3663#dl
I installed the drivers from Gigabyte which are from 2010.
I don't have the latest Catalyst but one from 2010 that installed with the driver...