How to Fix High CPU Usage by MsMpEng.exe

Windows 10 has recently faced high CPU usage after the KB4512941 update. And now, Windows 10’s Antimalware service is causing high CPU usage. Many users have complained that the Antimalware service (MsMpEng.exe) is continuously using high CPU in the background. Fortunately, you can easily fix high CPU usage by the MsMpEng.exe process.

Many users doubted MsMpEng.exe to be a virus. But interestingly, it is Windows 10’s Antimalware Service Executable (a system service) and not a virus. MsMpEng.exe service is controlled by Windows Security (former Windows Defender) itself. So, in order to reduce the high CPU usage by MsMpEng.exe, we need to disable it. The process is not very straightforward but you can do it.

NOTE: This issue seems to be fixed in recent Windows 10 update. But if you are still facing the issue, you can follow this tutorial.

Disable MsMpEng.exe and Fix the High CPU Usage Issue in Windows 10

Many users have identified the issue to be with the database file (mpenginedb.db) used by Windows Security. And because of some false positive entries in the database file, Windows Security keeps scanning the whole disk causing high CPU usage. So, in this tutorial, we will disable Antimalware Service Executable and delete mpenginedb.db file to fix the high CPU usage issue in Windows 10. Follow these steps.

Step 1: Open Windows Security

Mpenginedb.db is a system file that is related to the antivirus, so, it can not be deleted normally. We will need to disable Windows Security temporarily. After that, we will be able to delete the mpenginedb.db file. So, first of all, open Windows Security and select “Virus and threat protection” from the left pane. Now, click on the “Manage Settings” link under the Virus & threat protection settings.

Open Windows Security And Click On Manage Settings Under Virus And Threat Protection Settings
Open Windows Security and click on Manage Settings

Step 2: Disable Windows Security Temporarily

Here, turn off the toggles for all services one by one. It will disable Windows Security completely. Don’t worry it’s temporary, settings will be changed to normal later.

Disable All Features Of Windows Security Windows Defender - fix high cpu usage by msmpeng.exe
Disable Windows Security

SEE ALSO: How to Disable Windows Security (former Windows Defender) in Windows 10?

Step 3: Start Windows 10 in Safe Mode

After disabling Windows Security, we need to start Windows 10 in Safe Mode in order to disable MsMpEng.exe and fix the high CPU usage issue.

So, first, go to Settings > Update & Security. Here, select Recovery from the left pane and click on Restart Now button under Advanced Startup.

Go To Recovery Settings And Click Restart Now Under Advanced Startup
Settings > Recovery > Advanced Startup > Restart Now

Next, you will see Advanced Startup settings. Go to Troubleshoot > Advanced Options > Startup Settings > Restart. After restart, you will see Startup Settings, press the F4 or number 4 key to boot into Safe Mode.

In Startup Settings Press F4 Or Number 4 Key To Boot Windows 10 Into Safe Mode
Press F4 or Number 4 Key to Boot into Safe Mode

SEE ALSO: How to Start Windows 10 in Safe Mode?

Step 4: Disable MsMpEng.exe via Registry Editor

Once you have booted successfully into the Safe Mode, open Registry Editor. Type regedit into RUN and press Enter. If you see UAC Prompt, click Yes.

Go To Run Type Regedit And Press Enter Or Click Ok
RUN > type “regedit” > Press Enter

Copy and paste the following address in the Registry Editor’s address bar and press Enter. Windows Defender folder will open in Registry Editor.

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows Defender

Here, right-click on the blank space and go to New > DWORD (32-bit) value.

Go To Windows Defender Folder In Registry Editor And Create A New Dword
Go to the Windows Defender folder in Registry Editor and create a New DWORD

Name this new DWORD DisableAntiSpyware. After creating the DWORD, right-click on it and select Modify. Now set its Value data to “1”. We have successfully disabled MsMpEng.exe and we are almost there to fix the high CPU usage issue in Windows 10.

Modify Disableantispyware Dword And Set Its Value To 1 - fix high cpu usage by msmpeng.exe
Modify DisableAntiSyware DWORD’s value to 1

Close Registry Editor and restart your PC.

Step 5: Delete mpenginedb.db File to Fix High CPU Usage

It’s time to delete mpenginedb.db database file. We will use Windows PowerShell to delete this file. So, now search for “powershell” and click on Run as Administrator from the search results to open PowerShell as an Administrator.

Search For Powershell In Start And Select Run As Administrator
Run PowerShell as Administrator

After that, copy the command below and paste it into your PowerShell window. Following that, hit Enter. This will delete the mpengine.db file from your PC.

Remove-Item 'C:\ProgramData\Microsoft\Windows Defender\Scans\mpenginedb.db'
Remove Mpenginedb Db File To Fix High Cpu Usage By Msmpeng Exe
Remove mpenginedb.db file to fix high CPU usage by MsMpEng.exe

NOTE: If you get an error while deleting the mpenginedb.db file, you can try restarting your PC in Safe Mode. After booting into Safe Mode, you can run the above command again to delete the mpenginedb.db file.

Step 6: Revert the Changes

After deleting mpenginedb.db file to fix the high CPU usage issue by MsMpEng.exe (Antimalware Service Executable), we need to revert the changes we did in Registry Editor. Go to the same path in Registry Editor again and delete the “DisableAntiSpyware” DWORD.

Delete Disableantispyware Dword From Registry Editor
Delete DisableAntiSpyware DWORD from Registry Editor

After deleting the DWORD, close Registry Editor and restart your computer. After restarting the PC, Windows Security will start working again.

Restart Your Computer
Restart Your Computer

After restarting, you will not see high CPU usage by MsMpEng.exe (Antimalware Service Executable). If your issue is not fixed yet, you can try resetting your Windows 10 or reinstalling a fresh copy of Windows 10. You can also use a third-party antivirus like Quick Heal or Malwarebytes.

Disable MsMpEng.exe on Your Windows PC to Fix High CPU Usage

The above tutorial explained how you can delete mpenginedb.db file and fix high CPU usage by MsMpEng.exe (Windows’ Antimalware Service Executable). After we cleared the Windows Security (former Windows Defender) database, it won’t cause high CPU usage by scanning the whole disk.

We hope you liked this tutorial. In case you are still facing any issues, feel free to write them in the comment section down below.

SEE ALSO: Speed Up Your Windows 11 and Windows 10 in Easy Steps.

Editorial Staff

Hi there, we are the editorial staff at WINDOSPC (former HELLPC). We are a team of funny and technical people. Feel free to get in touch with us via Contact-Us page.


  1. Hi!
    thanks for your help.
    But at step 5, PowerShell tells me the adress doesn’t exist. After checking, it’s however the right address.
    can you help me ?


    1. You can manually check if the “mpenginedb.db” file exists at the “C:\ProgramData\Microsoft\Windows Defender\Scans” path. If it exists, you can manually delete it or rename it.
      You can follow the rest of the steps after that.

  2. It worked! At the end of Step 5, I restarted in regular mode, and it didn’t work. I went back and re-did the regedit step, and restarted in safe mode, and bingo! Thank you! You might want to add that for dummies, though:)

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