How to Update Microsoft Security Essentials (MSE) Virus Definitions Using Command Line and Without Using Windows Automatic Update

If you use Microsoft's free and excellent anti-virus and anti-spyware product "Microsoft Security Essentials", you might already know that it updates its virus definition files using Windows Automatic Update.

If you have disabled Windows Automatic Update, MSE will not update the virus definitions. Then what to do in this case?

Don't worry! In this topic, we'll tell you how to update MSE virus definitions using a built-in MSE command? You don't need Automatic Update enabled to use this command.

=> Simply provide following command in Command Prompt or Start Menu Search box or Run dialog box:

For version 1.0:
"%programfiles%\Microsoft Security Essentials\MpCmdRun.exe" SignatureUpdate

For version 2.0:
"%programfiles%\Microsoft Security Client\Antimalware\MpCmdRun.exe" SignatureUpdate

It'll open a Command Prompt window which will show you a message "Signature update started...". It might take a few minutes depending upon the size of virus definition files.


You can also create a shortcut for the command and place it on Desktop or Quick launch toolbar or pin it to Windows 7 Taskbar. You can even schedule a task for the above mentioned command using Windows Task Scheduler.

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Posted in: Troubleshooting

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  • how can i hide the command prompt window?? any arguments, keywords, tricks to task scheduler??

  • VG

    ^^ You can create a new shortcut for the command and then enter into its Properties and set it to Minimized.

  • ^^ Well it only works on desktop shortcut not in task scheduler!! :(

  • VG

    ^^ Try to enable "Hidden" option which is present at the bottom of first tab in Task Properties.

  • ^^ Already enabled...!!!! not working.. by the way, what is "start in(optional)" below "arguments(optional)" in edit action dialog box?? :/

  • Hello
    i am getting below error.

    C:\Program Files\Microsoft Security Client>mpcmdrun.exe signatureupdate
    Signature update started . . .
    ERROR: Signature Update failed with hr=8024002E
    CmdTool: Failed with hr = 0x8024002E. Check C:\DOCUME~1\A548230\LOCALS~1\Temp\Mp
    CmdRun.log for more information

  • -------------------------------------------------------------------------------------
    MpCmdRun: Command Line: mpcmdrun -removedefinitions -all
    Start Time: ‎Sat ‎Aug ‎10 ‎2013 14:08:52

    Start: MpRemoveDefinitions(1)
    Finish: MpRemoveDefinitions()
    MpCmdRun: End Time: ‎Sat ‎Aug ‎10 ‎2013 14:08:52

    MpCmdRun: Command Line: mpcmdrun.exe signatureupdate
    Start Time: ‎Sat ‎Aug ‎10 ‎2013 15:48:18

    Start: MpSignatureUpdate()
    Update started
    Search Started (MU/WU update) (Path:
    Update failed with hr: 0x8024002e
    Update completed with hr: 0x8024002e
    ERROR: Signature Update failed with hr=8024002E
    MpCmdRun: End Time: ‎Sat ‎Aug ‎10 ‎2013 15:48:20

  • I got solution but works only one time

    Click Start, click All Programs, click Accessories, and then right-click Command Prompt, and then select Run as administrator.

    In the Command Prompt window, type the following commands and press Enter after each command:


    Cd program files\microsoft security essentials

    Mpcmdrun –removedefinitions –all


    Restart your PC.

    Open Microsoft Security Essentials, click the Update tab, and then click Update. If the issue persists, go on to the next step.

  • i know how to enable it via task scheduler but i want that the end user dosent know that update is running.

    Is this possible?Like the scheduler runs in background hidden

  • Well, for Windows 10, I'd run "%programfiles%\Windows Defender\MpCmdRun.exe" SignatureUpdate

  • I was always getting the same error over and over:

    Signature update started . . .
    ERROR: Signature Update failed with hr=80070422
    CmdTool: Failed with hr = 0x80070422. Check C:\Users\Phil\AppData\Local\Temp\MpCmdRun.log for more information

    Then I read the whole help of that command, and you need to run it like this in order to avoid WUpdate and connect directly to the MS Servers, from the MSE directory:

    MpCmdRun.exe -SignatureUpdate -MMPC

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