I recently installed a genuine copy of Windows 8 from school because I need some Windows program for my classes. Everything has been working great for the past month but ever since yesterday I always need the charger plugged in. If I boot Windows 8 it just stays on a black screen until I plug the charger in then it shows up. Whenever I unplug the charger it goes back to a black screen, the macbook is 100% charged. Is there something I can do to fix this?