If your system has been hit by any of the malware around and you are unable to remove it from your machine or even are unable to start your system then here is an interesting and useful tool to your rescue. The tool is actually a recovery tool which can be installed on a USB or burn into a CD for booting.
The tool is recently launched by Microsoft and thus is in a Beta stage. The tool is called System Sweeper and has been designed such that users are able to use this tool to start an infected PC and perform offline malware scans including the rootkits. The tool works great for occasions when the malware prohibits users to install any software in the system. This is what a recovery tool you will need in this case.
The tool is free to use and is available in both 32-bit and 64-bit versions. The tool shall require around 250MB of space so it is still possible to install it in the USB drive, if not on CD. The tool is designed to work on Windows OS including Windows 7 and on both 32-bit and 64-bit versions.
Make sure you have the right version of the tool and the internet connected. For more info, you can read the homepage.