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 software—including 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.

The tool creates a log file named mrt.log in the %WINDIR%\debug folder. This tool is not a replacement for an anti-virus product. To help protect your computer, you should use an anti-virus product.