My ASUS A53SV laptop has an onboard Intel GMA graphics and also nVidia GeForce 540N. I am using Windows 7 Pro. I thought that the GeForce was not being used, so I went to Device Manager and disabled Intel graphics.
After that, my screen turned black and I could't see anything. I turned the laptop off and turned it on again – 'Resuming Windows' logo appears and then I only see a blinking cursor on a black screen.
I can't get into safe mode by hitting F8 and I can't enter BIOS either as usually (by holding Alt+F2 when ASUS logo splashes).