Hi I tried to install Windows 10 as dual boot on my iMac (late 2009) High Sierra. First I ran into this problem someone else also had here, which is unfortunately unanswered. Anyway since I couldn't use
Boot Camp Assistant, I created a bootable usb stick and installed windows manually. This worked quite well.
So I reinstalled windows 10 but they same happened, when the screen went to sleep (restarting didn't restore normal screen).
What can I do? Does this sound like a windows problem? Or is it due the fact that I am booting it on a Mac? Is there hardware incompatibility? I mean it works fine until the screen goes sleeping. I could reinstall windows and turn off screen sleeping as fast as possible but then something will possibly trigger this again.