How can I use my built-in ATI Radeon instead of Intel HD Graphics for OpenGL?
You probably have Intel HD Graphics integrated inside your Intel CPU, and additionally you have the AMD Radeon.
Firstly, download and install the newest drivers for your AMD graphics card from the AMD website. Windows comes with some drivers but usually they can't handle modern OpenGL.
Secondly, check your BIOS - you'll probably have an option to enable/disable those GPUs so that you could choose which one to use.