Suspect a common malware infection and want a focused cleanup scan? Microsoft’s Malicious Software Removal Tool (MSRT) checks for prevalent malware families, removes detected threats, and reverses changes they made.
A focused malware scan
MSRT is designed to find and remove prevalent malware families. After a detection, it can also reverse changes made by the threat. Windows Update delivers the tool automatically when automatic updates are enabled, and its integrated copy runs in the background.
For a manual check, run the standalone tool on demand. This workflow is aimed at investigating a suspected infection or adding a targeted scan alongside an existing antimalware product. MSRT covers selected prevalent threats, so it does not provide comprehensive malware detection.
What happens after a scan?
The standalone version displays a results report after scanning and removing threats. It also writes a log file named mrt.log in the Windows debug folder; administrators and support staff can use that record to see scan results.
- Run the standalone version when an on-demand scan is needed.
- The report identifies threats the tool found.
- The log is stored at %windir%debugmrt.log.
Windows Update and administration
If automatic updates are on, Windows fetches a fresh copy each month and runs it silently. The standalone copy provides a way to start a scan directly. Running the tool requires local administrator privileges.
Pros
- Removes prevalent malware and reverses changes it made
- Runs automatically through Windows Update
- Standalone scans produce a threat report and MRT.log
- Supports on-demand scans
Cons
- Targets only widespread malware families, not every threat
System requirements: Windows 7, Windows 8.1, Windows 10, Windows 11 · Local administrator privileges required
Does MSRT provide ongoing antivirus protection?
No. It scans for prevalent malware families and removes detected threats; it is not comprehensive antimalware protection.
Where can I find the scan results?
The standalone tool displays a results report and saves a log at %windir%debugmrt.log.
Can MSRT run without opening it manually?
Yes. When automatic updates are enabled, Windows downloads and runs the integrated tool in the background.