Microsoft Standalone System Sweeper Beta is a recovery tool that can help you start an infected PC and perform an offline scan to help identify and remove rootkits and other advanced malware. In addition, Microsoft Standalone System Sweeper Beta can be used if you cannot install or start an antivirus solution on your PC, or if the installed solution can’t detect or remove malware on your PC.
Microsoft Standalone System Sweeper Beta is not a replacement for a full antivirus solution providing ongoing protection; it is meant to be used in situations where you cannot start your PC due to a virus or other malware infection. For no-cost, real-time protection that helps guard your home or small business PCs against viruses, spyware, and other malicious software, download Microsoft Security Essentials.
Thanks to Copernic for the tip in Back Page News.