The following is a brief collection of open-source and/or free tools I regularly use for various system recovery tasks. If the servers you work with have CD drives, I would recommend burning these images onto a CD or DVD. This would save you the trouble of messing with the boot options in the BIOS. More advanced versions of BIOS can mount remote ISO images and boot from those. In most cases, however, this approach requires using the dreaded Internet Explorer an requires Windows.

Linux

• Ubuntu Rescue Remix – one of the best all-around Linux recovery LiveCDs. Download the ISO, burn to disk, boot from CD, fix your Linux box.
• SystemRescueCD – another comprehensive LiveCD with numerous system recovery tools for Linux.
• Trinity Rescue Kit – a Linux-based LiveCD designed primarily for Windows recovery and virus removal tasks. It can also be used to recover Linux systems.
• KNOPPIX – the all-time favorite Linux distro designed to boot just about anything with a CPU.
• GParted Live – a filesystem recovery and configuration LiveCD. Provides certain advanced tools for working with Linux filesystems not found in other LiveCD compilations. Can come in handy.
• DDRescue – not a LiveCD – this needs to be installed on a Linux system. This tool is very useful for copying data from attached hard drive suffering from I/O errors.
• SafeCopy – similar to DDRescue, this tool also needs to be installed on a Linux system. It will help you copy whatever data that can still be saved from an attached failing drive.
• Ultimate Boot CD – a LiveCD tool for Windows and Linux.

Windows

• Ophcrack – Windows password recovery LiveCD. Download the ISO, burn the CD, boot your Windows PC from the CD, recover admin password.
• Trinity Rescue Kit – a Linux-based LiveCD designed primarily for Windows recovery and virus removal tasks. It can also be used to recover Linux systems.
• BitDefender Rescue CD – one of my favorite antivirus tools for Windows. Download the ISO and burn to CD; it will boot a Linux OS and run a comprehensive virus scan. This helped me fixed more virus-infested Windows boxes than I care to count.
• F-Secure – a KNOPPIX-based antivirus and system recovery LiveCD designed primarily for fixing Windows systems.
• Hiren’s BootCD – a LiveCD compilation of huge variety of Windows system administration and recovery tools. You’ll need a few pots of coffee to get familiar with all the software crammed into this CD image.
• Ultimate Boot CD – a LiveCD tool for Windows and Linux.