The Avira AntiVir Rescue System a linux-based application that allows accessing computers that cannot be booted anymore. Thus it is possible to repair a damaged system, to rescue data or to scan the system for virus infections. Just double-click on the rescue system package to burn it to a CD/DVD.
You can then use this CD/DVD to boot your computer. The Avira AntiVir Rescue System is updated several times a day so that the most recent security updates are always available.