Hello all. I've try to change my gtx 570m to 756m but screen display msi bootscreen and "freeze" finally i've got a black screen. I've success push del button before freeze but screen freeze on "enter boot option..." and finally black screen again... As i've a HP Zbook with dedicated GPU, i swap quadro with 765m to try vbios flash but i don't understand that the 765m comes with HP ID when i list device with nvflash (10DE, 11E1, 103C, 190A). The 765m was detected in hp windows but improperly work (warning in device mngt). I've try to flash with a msi vbios (flash success but device ID not change when i listed it again). I try again on ms1761 and no screen again but p boot to windows (sound confirmed it). Is someone can give me a trick to try before i'll sell it cause i'm losing my patience... thanks for reding me PS sorry for my english...