Hi, I have a HP Pavilion 15-ab022nl with these features: . Intel (R) Core (TM) i7-5500U CPU @ 2.40GHz . NVIDIA GeForce 940M . 8 GB of SDRAM DDR3L-1600 . 1TB SATA I tried to install Niresh Yosemite 10.10.1 but: . if I press 'send', screen remains on the logo of the red Apple; . but if I write -v, after a series of written the screen goes black. I tried so many commands (GraphicsEnabler = Yes / No, NPCI = 1, cpus = 0, = 0 dart, nv_disable = 1, IGPEnabler = No, -x, -s, -f) but no one works. Can anyone tell me how to fix this? One of the reasons I bought the PC was to install Yosemite and im desperate. Help me please.