See if Windows had installed automatically and from windows updates, the AMD driver 27.20.14501.28009.
If so, you have to uninstall that driver first (and keep an eye if windows updates install it again, after a while).
If you see that MS Update install it again, you can use "Microsoft Show or Hide updates troubleshooter", and hide that update.
After unistall that "MS" driver (if it the case), please install AMD GPU driver again.