Repair GRUB without using LiveCD

1. Search root disk.
   
   grub> search -f /vmlinuz -s root
   
   
2. Set root disk.
   
   grub> root ($root)
   
   
3. Use these commands to find out root disk's information.
   
   grub> ls -l ($root)
   
   
4. Set linux kernel. There are three ways to do it.
   
   
   1. Change the red number with your root disk number. If your root disk is (hd0, msdos1), then use /dev/sda1.
      
      grub> linux /vmlinuz root=/dev/sda1
   2. Change red text with your disk label, which can get by using ls -l ($root).
      
      grub> linux /vmlinuz root=LABEL=LABEL
   3. Change red text with your disk uuid, which can also get by using ls ($root).
      
      grub> linux /vmlinuz root=UUID=UUID
5. Set ramdisk.
   
   grub> initrd /initrd.img
   
   
6. Now, you can boot your system.
   
   grub> boot
   
   
7. When you are logged in, type this command from terminal to fix your grub menu.
   
   $ sudo update-grub