Tried two different BIOS updates with same result. Made sure boot order was correct. WIN 10 tries repair, asks to reboot, then inaccessible boot device error is given. SSD, Gigabyte Z77-D3H MB.
A BIOS update should not mess with the boot loader. Check your BIOS settings, the updated might have reset some advanced boot options. Check to see if secure boot or virtualization needs to be disabled.