Kernel panic - not syncing: Attempted to kill init! " Error

Follow the following steps.
1. Once you are at the grub screen, press c for command line.
2. On command line execute the following commands.
find /grub/stage2
find /etc/hosts
This will provide you the boot partition & the root partition nos. in the format (hd0,2) etc
If the root partition & boot partitions are same then execute the following commands.
root (hd0,2)
kernel /boot/vmlinuz-kernel version ro root=/dev/hda3
initrd /boot/initrd-version
boot
if the boot & root partitions are different then replace the root=/dev/hda3 with the value you get for root partition i.e. if you get (hd0,5) then replace the value with /dev/hda6.
If you still get the kernel panic message, recreate the initrd image using the mkinitrd command.

Hope this will work. 

Regards 

Kuldeep Sharma