Disable SecureBoot in the UEFI Firmware (BIOS) in Lenovo Ideapad Z580 to boot with CloneZilla to save an image of the hard disk. Remember, only Secure Boot should be disabled in the BIOS. You need not change the boot from UEFI to Legacy. When you enter the BIOS, you will find that the option to disable Secure Boot cannot be selected. To select it, you need to set up a password. On the very screen, enter a password, and you will be able disable secure boot. You need to remember this password, else if you forget it, you will not be able to do any changes to the BIOS at all.
Press the Novo button (small button next to the power button) on the laptop and you can choose to boot using the CloneZilla live CD.