Many times we found ourselves in a difficult situation when our system cannot load in the regular way, for example due to virus infection or some system file missing, etc.
In such conditions, Rescue CD becomes very useful. You can simply boot using the rescue CD and can scan your system, remove the virus, copy/delete files, create/delete partitions and many other system tasks.
So a Rescue CD is a boon for all of us.
Many respected anti-virus companies are providing their rescue CDs free of cost. So here we are sharing a few such free rescue CDs which you can download and burn for future use:

Kaspersky Rescue CD:

Kaspersky is one of the best anti-virus company and now its providing a rescue CD absolutely free which contains the latest Kaspersky anti-virus. So you can scan your system by booting your system using Kaspersky rescue CD.
Download Kaspersky Rescue CD

BitDefender Rescue CD:

BitDefender is also a great anti-virus software. It also provides a free rescue CD which comes bundled with latest BitDefender anti-virus. The best thing in this rescue CD is, when you boot using this CD and connects to Internet, it can update the virus definition.
Download BitDefender Rescue CD

Avira Rescue CD:

Avira is one of the best FREE anti-virus software and it also provides a free rescue CD. Its a Linux based CD which can help you in scanning your system for virus infection.
Download Avira Rescue CD (ISO)
Download Avira Rescue CD (EXE)

F-Secure Rescue CD:

Another Linux based Rescue CD which can help you to scan your system. It can also update the virus definition if an Internet connection is available otherwise you can manually update it using USB drives.
Download F-Secure Rescue CD

AVG Rescue CD:

AVG is one of the best FREE anti-virus and it also provides rescue CD. Its built on a Linux distribution platform and contains lots of useful system tools including anti-virus, midnight commander, simpler and several Linux tools like vi, openssh, ntfsprogs, etc.
Download AVG Rescue CD