Updating bootcamp drivers
I recommend you use this supported driver at this time.
However, the steps described below should still work if you want to make sure you have the latest and greatest unsupported driver from AMD for your Radeon R9-based Mac.
Some people who tried to install the Anniversary Updates reach Apple’s forums to complain about two issues they encountered upon, or when trying to install the Anniversary Update.
As the Anniversary Update is now available for free to all eligible users, even those who don’t run Windows 10 machines, but have a valid license, can install it, as well.