A common problem that comes up after installing Windows on a separate partition on the same machine as Debian or another Linux flavour - you loose the grub menu and Windows boots by default, or Linux does not boot at all. Get a bootable live USB or CD of the Debian version you are running and boot that. Open a terminal and install gparted to find out which partition that is your linux root partition sudo bash apt-get install gparted Run gparted and find out what partition that is your linux partition, then exit gparted again gparted Or use fdisk -l to find out Now mount the relevant parts so you get inside your system, replace sdXY with your linux root partition, sdc7 or whatever. mount /dev/sdXY /mnt mount --bind /dev /mnt/dev mount --bind /proc /mnt/proc mount --bind /sys /mnt/sys Jump in to the chroot chroot /mnt Now you can update grub update-grub This is has proven not to be enough, you need to install it to the drives too: grub-install /dev/sdXY Do exit a lot of times and then reboot. More info at https://sites.google.com/site/kotkamaahacklab/home/debian-jessie
This is a personal note. Last updated: 2016-03-22 12:20:37.