The error messages were the following:
udevadm settle is not permitted while udev is unconfigured ALERT! /dev/disk/by-uuid/)a8cc71e....071cd does not exist. Dropping to a shell
Was it a plague of St. iGNUcius because I have written an article about Windows?
After some research on Google, I found out the solution:
- Boot the system using the Ubuntu live CD. If Ubuntu automatically mount the hard disk partition, unmount it before proceeding. This can be done easily through Nautilus.
- Open a command prompt.
- Create a new folder in order to mount the HD:
sudo mkdir /mnt/newroot
- Mount the HD (sda1, in my case):
sudo mount /dev/sda1 /mnt/newroot
- Change the root directory:
sudo chroot /mnt/newroot
- Run the following command:
update-initramfs -u -k all
- Return to the old root and unmount the partition:
exit sudo umount /mnt/newroot