I had two BSOD since my last message, so we had to RMA a few days ago because I didnt have time anymore to take care of the computer since it was not mine, i had to leave the town. I wish I had time to combine this solution with some others i've seen on the internet people say it worked for them. (for instance forcing the nvidia card off, It was 'on' all the time since I had read it's what fixed the pb for someone; but i've just read forcing the integrated GPU 'on' fixes it...).