You turn your Intel on board graphics solution in the bios setting of the motherboard to off.
Then set the default graphics adapter in the Pci-e slot to the setting Pci-e slot of the bios as the option. Save the settings in the bios before exiting. restart the computer and it should work. You problem has nothing to do with steam or the games just the fact you have two graphics solutions running when you should only have one the ATI graphics card.