Hi, I started a separate thread about a issue similar to this, on an Acer Chromebook C720 with windows 8.1 installed, the inbuilt display works without the official Intel driver, but as soon as it is installed the screen goes black, I have actually found a way of making a monitor work through the HDMI port, but this may be the same issue causing the problem, it is reproducible on any C720 if you install windows 8.1.
Regards, Chris