I think I would have just booted in Safe Mode and reinstalled the old Radeon driver. I'd put that driver in a folder there on your desktop in case that happens again, and it'll be a quick fix next time.

Win10 has been rock solid for me with no issues on any of my machines... but I still have an old 2003 Dell laptop that has XP that I keep just like it is for interfacing with older telecom systems - Win10 doesn't know how to play nice with the old GUIs running microwave systems.