Windows Defender is the built-in antivirus and anti-malware solution for Windows 10. It can also protect you from ransomware using Controlled Folder Access. Windows Defender works very well as long as you follow all the best practices of how to use a computer and how to be careful on the internet.
However, sometimes Windows Defender's CPU usage may be really high, anywhere from 30% to 90%. If you open the task manager, you will see the actual CPU usage by Windows Defender next to "Antimalware Service Executable."
The Antimalware Service Executable process or MsMpEng.exe process is related to Windows Defender's real-time protection module. Due to any number of reasons like system crashes, malware infections, etc., the MsMpEng.exe may use huge amounts of CPU resources slowing down your system's normal operations.
If you are facing this issue, let me show you how to fix Antimalware Service Executable high CPU usage in Windows 10.
- Check for virus infections
- Exclude Windows Defender from scanning itself (recommended)
- Disable Windows Defender real-time protection
- Use third-party antivirus application
Method 1: Check for Any Infection on Your System
The first and foremost thing you should do to fix Windows Defender high CPU usage is see if your system is infected with any virus, malware, or adware. This is because your system might be infected and Windows Defender is actively trying to remove the infection from the system which in turn leads to high CPU usage.
1. To scan your system with Windows Defender, search for "Windows Defender Settings" in the start menu and click on the "Virus and Threat Protection" option.
2. We need to perform a deep or full scan. In the Threat Protection window, click on the link "Run a new advanced scan" appearing under the Scan Now button.
3. Now, select "Full Scan" option and click on the button "Scan Now."
Depending on your system, the scan may take a couple of hours to complete. So, sit back and wait until the scan finishes. If Windows Defender found any threats, it will remove them automatically.
Additionally, I also recommend you to scan your system with Malwarebytes Anti-malware.
After removing any malware or confirming that your system is not infected, proceed to the below solutions.
Method 2: Exclude Windows Defender Folder
Windows Defender always runs in the background and constantly monitors your system for any threats like viruses, malware, trojans, etc, all the while checking various system processes. This is generally called as real-time protection.
Since Windows Defender monitors all the processes, it includes itself in the scanning process. This can sometimes create a loop like situation where it tries to scan itself for unusual behavior thus a cause for Antimalware Service Executable high CPU usage. Funnily enough, to avoid MsMpEng.exe high CPU usage, you can add Windows Defender itself to the Windows Defender exclusion list.
Once you add Windows Defender to the exclusion list, Windows Defender will not scan itself constantly which in turn reduces the Windows Defender high CPU usage.
Personally, this is the method that worked for me. So there is a good chance it will work for you too.
1. First, search for "Windows Defender Settings" in the start menu and open it.
2. In the Windows Security window, click on the option "Virus and Threat Protection" under Protection Areas section appearing in the right panel.
3. In this window, select "Virus and Threat Protection Settings," scroll all the way down and click on the link "Add or remove exclusions" under the Exclusions section.
4. This is where you can add any folder, file, file type, or process to the Windows Defender exclusion list. Click on the "Add an exclusion" button and select the option "Folder."
5. In the Select Folder window, go to
C:\ProgramData\Microsoft\, select "Windows Defender" folder and then click on the button "Select Folder" to add Windows Defender folder to the exclusion list.
Note: You might receive UAC (User Access Control) prompt, just click on the "Yes" button to continue.
That is it. You've successfully excluded Windows Defender from the scanning process. Restart your system and you should no longer see high CPU usage for Antimalware Service Executable process.
If you are still experiencing the Antimalware Service Executable high CPU usage issue then you might want to follow the below methods too.
Method 3: Turn Off Real-Time Protection
If the above method did not work then as a last ditch effort disable Windows Defender's real-time protection. Since the Antimalware Service Executable high CPU usage is caused by real-time protection, disabling it will instantly solve the issue.
That being said, I do not recommend disabling real-time protection completely or for a longer period of time. Only treat this method as a temporary fix. Also, when you re-enable real-time protection, the Windows Defender high CPU issue many resurface again.
1. First off, open Windows Defender by searching for "Windows Defender Security Centre" in the start menu. Go to "Virus and Treat Protection" and click on the option "Virus and Threat Protection Settings."
2. On the right-panel, toggle the button under "Real-time Protection" to "Off." You will receive a UAC (User Access Control) prompt, click on the "Yes" button to continue.
That is all. Windows Defender will disable real-time protection and you will no longer face Antimalware Service Executable high CPU usage issue.
Again, this is just a temporary fix. DO NOT disable real-time protection for extended periods of time.
Method 4: Use Third-Party Antivirus Solution
If the above methods did not work for you and the Windows Defender's CPU usage is so high that you cannot use your system, you can ditch Windows Defender for third-party antivirus applications like Avast or AVG and Malwarebytes Anti-malware.
Just download and install Avast or AVG and Windows Defender will disable itself thus solving the MsMpEng.exe high CPU usage. Moreover, you will also get a bit more security compared to Windows Defender. Additionally, install Malwarebytes for better protection malware.
Hope the above methods help fix Antimalware Service Executable high CPU usage in Windows 10. Let me know of your experiences about using the above methods in the comment section below.