Linux Poison posted a guide about reinstalling GRUB 2 in Ubuntu using Live Distribution CD

GRUB 2 introduces many new changes. GRUB 2 has better portability and modularity, supports non-ASCII characters, dynamic loading of modules, real memory management, and more and is totally different from its predecessor, menu.lst doesn't even exist, it is replaced by grub.cfg which have little resemblance with menu.lst.

  How to reinstall GRUB 2 in Ubuntu using Live Distribution CD