I post before Article talking about “Hack Root Password With Protected Grub” Here .

But what if GRUB was Locked By password and you forget Root Password, There’s always away to do it but you need the same media for Operating system ( Never tried to use different distribution ) after boot :

In the above screen Type ” linux rescue ” and then Press enter

After follow the instruction and Enter Bash

chroot /mnt/sysimage [Enter]
cd /boot/grub [Enter]
vi menu.lst

Now In that file you see word “Password”  Remove Line, This will remove Grub password after save it the OS will Reboot but this time Grub will be UN-Protected , Remove CD and follow the normal instruction in Article Number one Here.

Thank you
Osama Mustafa