To check where grub is installed

Open terminal and run

sudo fdisk -l 2>/dev/null | egrep ”Disk /|/dev/” | sed ”s#^/dev/#Part /dev/#” | awk ’{print $2}’ | sed ’s/://’ | xargs -n1 -iX sudo sh -c ”dd if=X count=1 2>/dev/null | grep GRUB > /dev/null && echo Grub found: X || echo no Grub: X”

onko-grubia

grub-check