sp55430 f.48 modded doesn't save changes

[jean luc ferre]

Hello,
on an old laptop hp g72-b52sf i flashed new bios sp55430 f.48 that i found on this post :https://www.bios-mods.com/forum/showthre...ht=sp55430
but after flashing it's impossible to save the modifications of the vidéo configuration in advanced tab. i want to disable the dgpu because the driver that is loaded allways crashed my laptop with a blue-screen.
But when i do the modification of selecting the igpu and after saving normally with f10, when the reboot is made we see that the modification hasn't been kept; the video configuration has returned to "hybrid".
perhaps is there somebody who can explain me this fact and indicate me how to do to disable the dgpu which is an ATI chip.
Thank you in advance for your answers.
jean luc ferre