====== GRUB ======
Grub is a Linux bootloader.

===== Backup MBR using dd =====
Before installing Windows (backup of original MBR):
<code>sudo dd if=/dev/sda of=sda.linux.mbr bs=512 count=1</code>

After installing Windows (to have a backup):
<code>sudo dd if=/dev/sda of=sda.windows.mbr bs=512 count=1</code>

===== Restoring MBR using dd =====
Boot from recovery CD/USB, mount /home, navigate directory where the MBR backups are stored.
<code>sudo dd if=sda.linux.mbr of=/dev/sda bs=512 count=1</code>

===== Rebuilding MBR using CHROOT =====
(Complex solution, as above way using dd works just fine)
[[chroot]]
[[http://wiki.ubuntuusers.de/GRUB#Methode-3-Chroot-ueber-ein-Live-System]]