I was playing WoW this morning using my XFX 7870 under Windows 10. The displayed flickered for a moment, showed some lines, then some color distortion, then went black. Rebooting showed me the BIOS screen, but everything after that is black. No cursor.
Windows 10 self-repair did nothing, so I rolled it back to Windows 7. There, I get the BIOS screen, the swirling Windows boot animation, then black.
I coaxed it into Safe Mode, and the display is okay there. I uninstalled everything AMD from the computer. I rebooted, and the driverless Win 7 is okay. The AMD driver self-installs, and the subsequent reboots are BIOS->Windows animation->black.