The kernel and/or initrd files (specified in the /boot/grub/grub.conf entry that you are using) seem to be missing.
If you are at that grub prompt, you can find out which ones are available by using the find command. It's not well documented, but you can use the tab key for filename completion.
I'll assume that your kernel is named vmlinuz-something, and your initial ramdisk is initrd-something.
If your /boot directory is a separate partition mounted at /boot, you could type "find /vm", then hit tab and it'll show you all the kernel files; or type "find /init", then hit tab to see all the initial ramdisk files.
(If your boot directory is not a separate partition, then you'd do "find /boot/vm<tab>" and "find /boot/init<tab>"...)
Once you know the kernel and initrd files, reboot, interrupt grub by fitting 'esc', then edit the kernel and/or initrd statements to correct them, then 'b' to boot.
If that works and it boots, you can then correct your /boot/grub/grub.conf file.