If you have a switchable graphics chip on your laptop your laptop will switch depending on the demands of applications. No need to disable one or the other, some laptops are design like this in order to switch back and forth. When there are no heavy demands the laptop will use Intel embedded graphics since power consumption is much lower than say an NVidia or AMD GPU chip.
To be honest disabling a driver
to stop one or the other from starting may just cause more problems. You may be able to make those kinds of changes inside AMD Catalyst software or Intel Control Manager safer to do changes from here.