• Grub boot: https://www.ubuntubuzz.com/2016/03/booting-gnulinux-manually-with-grub-prompt.html

# example
set root=(hd0,3)
linux /boot/vmlinuz-4.2.0-16-generic root=/dev/sdb3
initrd /boot/initrd.img-4.2.0-16-generic
boot

create boot item in windows booter: https://www.jianshu.com/p/6bc9b14757c7 how to delete it:

• Find {id}: bcdedit /enum
• delete it: bcdedit /delete {id} /f