Windows 10 Safe Mode Notes

If in Windows, can right click Restart and go through the graphical menus (before shutdown) for
Advanced Troubleshooting, Startup Option

or in elevated command prompt (use Windows+X)
try adding
bcdedit /set {bootmgr} displaybootmenu yes

then restart and hit F8 from simple menu
see
http://www.nextofwindows.com/how-to-boot-to-safe-mode-straight-from-f8-key-in-windows-8



ALSO, other options
http://www.howtogeek.com/245175/how-to-add-safe-mode-to-the-windows-8-and-10-boot-menu/

Also Shift F8 when coming up
  or try shutting down

IF 30 says has gone by on Windows 10
look for the two hidden folders
show OS choices
or advanced option - revert to prior build