Since you did a clean install then there is no software issue here. Things you can check are RAM of the laptop. If it was more then 1 stick remove them all and run it with one. Could just be the MB or the GPU are basically damaged. You could try to update BIOS and see if that helps. Not much else you can do. "atikmpag.sys" is triggered from so many things. I had BSOD too from "atikmpag.sys" and it was system memory not stable and had to set timings manually but you having a laptop such things are not possible.