Where is the brightness congtrol hidden in Win 7 64bit using Radeon HD6450 video card

How does this user turn down the brightness of the Display Screen? 

The Graphics Card is a Radeon HD6450

The AMD Radeon Catalyst Driver version is 15.7.1 is claimed to be the correct driver for my

PC, but I have yet to find a Brightness Control!  Where is it hiding?