Super Grub2 Disk is a bootable floppy, CDROM, or USB system which lets you boot into your system. It is simply a Grub2 disk with a lot of useful menus. It can try to autodetect all of your operating systems, load your grub.cfg configuration file, and load grub2's core.img, even if the mbr is damaged. It has multi-language support.
Rescatux is a GNU/Linux rescue CD that comes with Rescapp, a nice wizard that will guide you through your rescue tasks. It can restore Grub to the MBR update a Grub configuration, perform filesystem checks, fix a Windows MBR, and more. Features that can indirectly assist the rescue process include chat programs to let you reach human online help, a share log (automatic pastebin), and a share log that uses formatting appropriate for posting on a forum.