My parent’s computer recently refused to boot, with the error message “Target Filesystem doesn’t have /sbin/init”, following by booting to BusyBox.

I was able to fix this by:
– Booting into Ubuntu from a Live CD
– Going into GParted and figuring out what the mount location of my linux partiton is on (it was /dev/sda6).
– Then running the following command from the terminal:

e2fsck -f -y -v /dev/sda6

This command repaired the file system, and when I rebooted Ubuntu was working again.