Hi, Yesterday I was playing a computer game, when my pc suddenly shut down, so I restarted and tried again, and the same thing happened. So I figured the PC might be overheating, I told my dad, who got rid of the dust inside the PC. But after putting all the cables back into the pc, when we tried to restart the computer, all it did was show bios information (American Megatrends etc) After that the computer continues, but after it says "checking NVRAM... update OK!" it goes to a black screen with a white blinking underscore on the top right of the screen. I can't see any sign of windows whatsoever (I have windows Vista). I tried getting to the safe mode, which I read about after googling. But I can't enter safe mode, all I get is a screen saying "Please select boot device" and it shows 4 options: 3 "USB: Generic Flash" options and 1 "IDE:HL-DT-ST DVDRAM" option. But whichever one I choose, it just goes back to the black screen... I read about this on google too, and people said you should close this screen and keep pressing F8, but when I do, nothing happens, all I see is the black screen. Does anyone know what to do to fix the problem?