Can you see and access your original installation from the live environment? The GRUB directory should be in a mountable partition, usually root (may not be labelled as such).
E.g. when I boot into a LiveCD, I have two mountable partitions, one of 10GB (root) and one of 60GB (home). My menu.lst is in the /boot/grub/ directory of the 10GB partition.
Bookmarks