https://justhodl.blogspot.com/2018/02/ubuntu-windows-windows-10-grub.html
sudo cat /boot/grub/grub.cfg | grep windows
Windows Boot Manager (位於 /dev/sda2)
sudo gedit /etc/default/grub
GRUB_DEFAULT="Windows Boot Manager (位於 /dev/sda2)"
#GRUB_DEFAULT=0
sudo update-grub
sudo update-initramfs -u -k all
