All You need is Super Grub Disk.
1) Download
2) Burn it onto a Floppy
3) Select: GNU/LINUX > FIX BOOT OF GNU/LINUX (GRUB)
4) Select the Linux or Grub installation you want to restore
5) Reboot, Thats it
http://supergrub.forjamari.linex.org/
Do read quick_guide in documentation section of Website
http://supergrub.forjamari.linex.org...on#quick_guide