I have windows 10 set up with black screen screen saver with password (pin) protection upon coming out of screen saver. Most of the time it works, but twice today I've tried to wake the machine and just get a black screen with mouse pointer. I can move the pointer, but I can't get past that to type my pin, etc. My only recourse is to reboot the machine. I've tried ctrl-alt-delete, just entering my pin anyway, windows button, etc. to no avail. Any ideas?