In my case, my computer has dual boot with Ubuntu and Windows XP and today I need to format my Windows XP but I don’t want lose my entire Ubuntu. Now it’s different from in the old day experience, I usually lost every partitions after formatting Windows and I wasn’t aware that GRUB can be reinstall to get the boot menu back.

There are serveral ways AND there’s an easy way to recover this problem. Just though I’d post it here for my future reference and hoping it might help other as well.

Assumed that you have Linux CD handy. I use Ubuntu Live CD (Ubuntu 8.04 LTS Desktop Edition) at the time writing this article.

• Power ON PC
• Set your PC boot sequence to boot from CD first
• Insert Linux CD in the drive
• When system boot up, press any key to boot from CD
• List of languages displays, select you preferred language (English recommended)
• Select Try Ubuntu from the menu
• When you get to Ubuntu desktop, open the terminal and type the following command
  

  sudo grub

• At grub prompt, type
  

  find /boot/grub/stage1

• result will display underneath, it could be (hd0,0) or (hd0,1) depends on your the hard disk you have. Make sure you type in the parameter below correctly
  

  root (hd0,0)
  setup (hd0)
  quit

• Close the terminal
• Restart your computer
• You should see Grub menu to select which Operating System to boot