I'm having a serious problem with my laptop. Everything was working fine yesterday, but when I turned it on this morning, instead of booting up like normally I just get a black screen saying "No Bootable Device -- Please restart system". Well, I've reset the PC dozens of times throughout the day, and it hasn't seemed to work. I tried to find a solution online myself, but the only thing I could find was to hold the 0 key while turning the PC on, and it should do something, but when I do that, nothing happens. It still just goes to the "No Bootable Device" message. I'm at my wit's end. I depend on my PC for my daily life, so this is incredibly frustrating and stressful. Does anyone know what the problem could be?