Restore GRUB2 after installing Windows
How I Restored GRUB2 after a Windows 7 Install. GRUB2 (Grand Unified Bootloader)Â is a universal bootloader used by Ubuntu and other Linux Distributions. If you have a Linux Distribution installed on a partition, and attempt toÂ install Windows alongside it, your GRUB bootloader will be overwritten by the Windows bootloader, and your computer will only boot into Windows.
Recovering the GRUB2 Bootloader after a Windows InstallÂ is simple. When finished, your Bootloader should detect all installed Operating Systems and automatically add a bootable menu item for each of them.
Note: This GRUB2 Installation process assumes that a Linux Partition still exists. If you overwrote Linux with Windows, this tutorial will not work for you, as there is no Linux system to recover boot.
- Boot from an Ubuntu Live CD or Live USB
- Once up and running, Open a Terminal
sudo su(press enter after typing each command)
- Note which device contains your Linux partition (IE: /dev/sda1)
- Type mount /dev/sdx# /mnt (replacing x# with your actual device and partition number)
mount --bind /dev /mnt/dev
mount --bind /proc /mnt/proc
cp /etc/resolv.conf /mnt/etc/resolv.conf
grub-install --recheck /dev/sdx (replacing x with your actual device)
reboot(to reboot your PC)
Make sure to remove your Live USB or CD. Upon reboot you should be presented with a GRUB2 menu. However, Windows is missing. Now, I show you how to fix that.
Making GRUB 2 detect Windows Installs:
- Proceed to boot into your Linux environment.
- Open a terminal and type
sudo update-grub(enter your root password when prompted)
If all went well, grub should have updated the menu entries to reflect what it detected. Including existing Windows partitions.