What to do:
Put the Linux liveCD or boot disk you created while the installation; on the floppy drive, boot the system and run grub command
Remember that for grub (hd0,1) means hda (primary controller master), second partition.
Now we need to tell grub where are the grub files:
If you know where they are, type something like:
else if you have no idea, type:
and then the root command with the correct parameters:
to install it on hd0, that is MBR of the first HD.
type quit and reboot.
The menu will appear again.
If you want to make some changes to the boot menu, you must edit the file: /boot/grub/menu.lst
$ gksu gedit media/disk/boot/grub/menu.lst