Weird issue.
Since the last lot of MS updates I've had to uninstall AB 4.1.1 as the the system just won't run with it loaded.
I've changed the driver up to 353.06 and rolled it back to 347.88 using DDU and it made no difference. As soon AB loads on boot the system hangs and eventually reboots to the lock screen.
Uninstalled AB - and calm is restored.
Any ideas ?