This tool will help to remove specific, prevalent malicious software from infected systems. Because computers can appear to function normally when infected, Microsoft advises you to run this tool even if your computer seems to be fine. In addition to using this tool, you should use an up-to-date antivirus product to help protect your computer from other malicious software. For more information, see
Protect Your PC.A new version of this tool is released on the second Tuesday of every month. These new versions will be available from the Microsoft Download Center—this page—as well as from Windows Update / Automatic Updates. An
online version of the tool is also available. It is recommended that Windows XP users use Windows Update / Automatic Updates to download the tool. If you are using any other version of Windows for which this tool is supported, please download the tool from this page or run the
online version of the tool at least once a month to ensure that you are using the latest version of this software.
After the tool has been executed and the End-User License Agreement (EULA) is accepted, the tool automatically checks for infection by specific, prevalent malicious software and removes any found. When the detection / removal process is complete, the tool displays a message describing the outcome of the execution—including what malicious software, if any, was detected and removed. The tool can be safely deleted after it has run. Also, the tool creates a log file named mrt.log in the
%WINDIR%\debug folder.
Please review
KB890830 for the list of malicious software that the current version of the tool is capable of removing as well as usage instructions. Also, please be aware that this tool reports anonymous information back to Microsoft in the event that an infection is found or an error is encountered. The above KB article contains information on how to disable this functionality and what specific information is sent to Microsoft.
It is strongly recommended that you review
KB891716 before you consider deploying this tool in an enterprise environment.
The user must be an administrator to run this tool. This tool will not run on any version of Windows 98, Windows ME, or Windows NT 4.0.