1. Home
  2. Windows

FIX the Antimalware Service Executable High CPU Usage (MsMpEng)

Windows 10 runs quite a few services in the background. These services normally do not take priority when it comes to using system resources. User processes are generally given priority. There will be times when certain Windows processes take precedence though and these processes then take up more CPU power. If you’re seeing high CPU usage by Antimalware Service Executable (MsMpEng), and it’s consistent, you may need to look into it, and possibly fix a problem or two.

Antimalware Service Executable (MsMpEng)

The Antimalware Service Executable (MsMpEng) is basically Windows Defender. It is going to run all the time so if you see it in Task Manager, it’s nothing to worry about. The worrying thing is if it’s consistently using a lot of the CPU’s power. If your system is idle, the CPU usage will go up since Windows Defender utilizes the downtime to run scans but you should not be seeing consistent high CPU usage from this process.

Antimalware Service Executable High CPU Usage

FIX: Antimalware Service Executable High CPU Usage (MsMpEng)

1. Restart the system

Desktop computers don’t need to be shut down every night. Most do fine by going into a low-power state. This is fine until processes begin to stall. It’s a problem with Windows 10. Try restarting your system and see if usage by this process returns to normal (single digits, or low double digits).

2. Run a full scan

The high CPU usage by Antimalware Service Executable may be caused by a long-overdue scan that needs to run. Often, the simple solution is to allow a full scan to run. You will need to stop the service in its current state and then initiate a fresh scan. It is best not to use your system until the scan completes so that it completes faster.

  1. Open Windows Defender.
  2. Go to Virus & Threat Protection.
  3. Click Manage Settings under Virus & threat protection settings.
  4. Turn off all the switches.
  5. Restart the system.
  6. Once you’re back on your desktop, turn all the Virus & threat protection settings back on.
  7. Return to the main Virus & threat protection tab.
  8. Click ‘Scan Options’.
  9. Select ‘Full scan’ and click the ‘Scan now’ button.
  10. Allow the scan to complete.

3. Reset Windows firewall

Windows firewall has certain rules that users can modify according to their needs. As you install apps, you will often have to allow some exceptions for the firewall. VLC player is one common example of an app that asks for exceptions. While generally harmless, these rules may interfere with Windows Defender, and resetting the rules may fix the problem.

  1. Open Windows Defender.
  2. Go to the Firewall and network protection tab.
  3. Scroll down, and click Restore firewalls to defaults.
  4. Restart the system, and Antimalware Service Executable’s CPU usage should return to normal. You can add your exceptions back to the firewall later on.

4. Scan for malware

Windows Defender is not impervious. It can stop malicious files and apps from running but it isn’t going to be able to stop everything. It’s possible that your system is infected with something that is causing Windows Defender to work in overdrive. Try using a different scanning tool like the free version of MalwareBytes. It may disable Windows Defender while it runs but that isn’t something to worry about. Allow it to scan your system and remove any infected files. You can keep ‏MalwareBytes or you can go back to Windows Defender.

5. Exclude Antimalware Service Executable from Windows Defender

Antimalware Service Executable is one of many services that Windows Defender runs but it is not the sum total of all services that the antivirus runs. Sometimes the high CPU usage by Antimalware Service Executable is because Windows Defender is scanning the Antimalware Service Executable service which it shouldn’t. You can add this service as an exclusion and it will bring its CPU usage back down to normal.

  1. Open Windows Defender.
  2. Go to App & browser control
  3. Under Exploit Protection, click on Exploit Protection Settings.
  4. Go to the Program Settings tab.
  5. Click the ‘Add program to customize’ button.
  6. Select ‘Add program by name’.
  7. Enter the following and click ‘Add’.
  1. Restart the system.

6. The nuclear option

The above solutions are all simple but if your problems persist there are a few other things you can try that are a bit more extreme.

  1. You can try creating a new user account and deleting the one that you’re experiencing the high CPU usage from Antimalware Service Executable.
  2. You can reset Windows 10 and keep all your apps and files.
  3. You can perform a fresh install.


You will find plenty of online advice telling you to uninstall Windows Defender to get rid of this problem and that will work. It will also leave you without an antivirus and we don’t generally recommend something like that. Windows Defender keeps your system and if you decide to remove it, you should replace it with another anti-virus. Likewise, changing how the Windows Defender works isn’t a good idea. Try one of the nuclear options we’ve listed or make sure you have a robust alternative available before you remove it.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.