This might be a long stretch, but are you perhaps using a Radeon graphics card? I’ve had the exact same issue happening for a while now whenever I launch WoW. I’ve also had some other games like OW or Dota2 blackscreen my computer.
After a few days of searching for known issues, I realized, that the new AMD Radeon Software that uses a feature called “Wattman”, to regulate your gc’s power consumption and output, might accidentally overload the gc and cause it to crash or work incorrectly. So the solution was to either rollback the drivers to somewhere in November, where the Radeon Software feature was an option during install and you could skip it, or the second idea, as soon as Windows start up, go to task manager and shut down the “Radeon AMD Software Host” and “Radeon AMD Software Overlay” processes. This seems to fix the issue and I have 0 problems from there on.
NOTE: There are comments online about a similar issue with GeForce gc’s, same solution, close down the software and overlays if there are any. This does not effect the drivers!
TL;DR: If using Radeon gc, use task manager to close “Radeon AMD Software Host and Overlay” processes.
Hope this helps!