Updating Microsoft Security Essentials Using Command-Line

Microsoft Security Essentials includes a command-line utility which can be used to update the virus/malware definitions, initiate a scan, undo a recent definition update and perform other tasks. To know how to use the command-line utility, open a Command Prompt window (CMD.EXE) and execute the following command:

"%ProgramFiles%\Microsoft Security Essentials\MpCmdRun.exe" /?

Command Description
-? / -h Displays all available options for this tool.
-Trace [-Grouping #] [-Level #] Starts diagnostic tracing
-RemoveDefinitions [-All] Restores the installed signature definitions to a previous backup copy or to the original default set of signatures
-RestoreDefaults Resets the registry values for Microsoft Antimalware Service settings to known good defaults
-SignatureUpdate [-UNC] Checks for new definition updates
-Scan [-ScanType] Scans for malicious software
-Restore -Name <name> [-All] Restore the most recently or all quarantined item(s) based on name
-GetFiles Collects support information

In addition to the above information, detailed information for each command-line parameter is shown when you run the above command.

To update the MSE virus/malware definitions, use this command:

"%ProgramFiles%\Microsoft Security Essentials\MpCmdRun.exe" -SignatureUpdate

The command-line tool can be useful if you want to update MSE using Batch file, Script or using Task Scheduler.

About the author

Ramesh Srinivasan founded Winhelponline.com back in 2005. He is passionate about Microsoft technologies and has a vast experience in Windows — delivering support for Microsoft's consumer products. He has been a Microsoft MVP (2003-2012) who contributes to various Windows support forums.

4 thoughts on “Updating Microsoft Security Essentials Using Command-Line”

  1. I was able to update the virus definitions with the following code:
    cd “%ProgramFiles%\Microsoft Security Essentials\”
    MpCmdRun.exe -SignatureUpdate

    But unable to start a scan with the following code in the same batch file:
    START msseces.exe -Scan -ScanType 0

    what gives?

  2. ———-UPDATE-MSE.CMD———-

    @color F3
    @timeout /t 40
    @echo off
    “C:\Program Files\Microsoft Security Client\MpCmdRun.exe” -SignatureUpdate -MMPC
    @timeout /t 10


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