System rescue
Tools for system recovery. These tools are, mostly, Live CDs.
Clonezilla
Backup and restore partitions and hard drives. Free software alternative to Norton Ghost and Drive Image.
GParted Live CD
http://gparted.sourceforge.net/livecd.php
Tool for hard disk partitioning. Supports resizing partitions.
SystemRescueCD
Bootable system recovery CD based on GNU / Linux. Contains a multitude of tools, including Parted.
Ultimate Boot CD
http://www.ultimatebootcd.com/
Bootable system restoration CD. Enable to recover a hard disk with bad sectors (low level format).
Super Grub Disk
Recover a damaged MBR. Must-have tool to boot a GNU/Linux system after installing Windows.
Windows Defender Offline (beta)
http://windows.microsoft.com/en-US/windows/what-is-windows-defender-offline
Scan a computer with Microsoft Windows Defender without booting the operating system.
Kaspersky WindowsUnlocker
http://support.kaspersky.com/faq/?qid=208285003
Recover a Windows computer totally trashed by a virus.