recuprar ubuntu

Try this:

    Switch on your computer. Boot into a Ubuntu Live DVD/USB
    After the load, open a terminal,

    Press Ctrl+Alt+T

    Run in it:

    sudo -i
    fdisk -l

    Fdisk will inform you as your partition / (root) called, say it as in the post /dev/sdb1, continuous running:

    umount /dev/sdb1
    fsck -y /dev/sdb1
    reboot

    Remove the DVD/USB and boot from the SDD