Today, Microsoft released the new Malicious Software Removal Tool. The link below contains information about the tool, along with links to the scanner and downloads:
Malicious Software Removal Tool
The Microsoft Windows Malicious Software Removal Tool checks Windows XP, Windows 2000, and Windows Server 2003 computers for and helps remove infections by specific, prevalent malicious softwareincluding Blaster, Sasser, and Mydoom. When the detection and removal process is complete, the tool displays a report describing the outcome, including which, if any, malicious software was detected and removed.