Why is Windows Defender constantly running?

Antimalware service executable is a component of Windows Security that runs in the background.

But sometimes antimalware service executable can impact Windows 10 computers negatively by using too much CPU.

In this guide, I will show you what antimalware service executable is, why it uses so much CPU, and how you can optimize your Windows 10 computer to make sure it doesn't use too much CPU.

Antimalware service executable is a Windows Security process that executes real-time protection against malware.

Also known as msmpeng.exe, antimalware service executable runs in the background so it can scan files and programs from time to time.

When an antimalware service executable detects a virus or other malicious attacks, it deletes them or quarantines them.

Why does Antimalware Service Executable use a lot of CPU?

The main reason that antimalware service executable uses too much CPU is that it runs constantly in the background.

While running in the background, it actively scans programs and files and carries out the appropriate actions whenever it detects anything malicious.

In addition, the antimalware service executable uses too much CPU because it scans its own folder - C:\Program Files\Windows Defender.

So, stopping antimalware service executable from scanning its own folder is one of the ways you can make it use less CPU.

How to Stop Antimalware Service Executable from using too Much CPU

The 2 main ways you can stop antimalware service executable from using too much CPU is to reschedule Windows Security scans and prevent it from scanning its own folder.

Rescheduling scans won't make scans happen all the time, and preventing the executable from scanning its own folder will disable real-time protection.

Solution 1: Prevent Antimalware Service Executable from Scanning its Own Folder

Step 1: Press the WIN key on your keyboard and select the gear icon to open the Settings app.

Step 2: Click on “Update and Security” from the menu tiles.

Step 3: Select “Windows Security”, then click on “Virus and threat protection”.

Step 4: The Windows Security app will open up. Under “Virus & threat protection settings”, click on the link that says “Manage Settings”.

Step 5: Scroll down to “Exclusions” and select the “Add or remove exclusions” link.

Step 6: On the next page, click on “Add an exclusion”, then select “Folder”.

Step 7: Paste “C:\Program Files\Windows Defender ” into the editor and click on “Select Folder”.

Step 8: Immediately after you click on “Select Folder”, a massive modal will appear – make sure you click “Yes”.

The folder selected will now be added to exclusions and will not be scanned.

Solution 2: Disable Realtime Protection and Reschedule Scans

Step 1: Press WIN (Windows key) to open the Run Dialogue.

Step 2: Type “taskschd.msc” and click “OK”. This will open up the Task Scheduler app.

Step 3: Expand the “Task Scheduler tab”, “Microsoft”, and “Windows”.

Step 4: Scroll down and select “Windows Defender”.

Step 5: Right-click on “Windows Defender Scheduled Scan” and select “Properties”.

Step 6: Uncheck “Run with highest privileges” in the general tab.

Step 7: Go to the Conditions tab and uncheck everything there.

Step 8: Switch to the Triggers tab and click “New”.

Step 9: Schedule the time you want Windows Defender to run scans. Choose the frequency, date, and time, then click “OK”. Click “OK” again.

Step 10: Restart your computer. With this, the antimalware service executable should not eat up too many CPUs again.

Final Thoughts

The protection offered by the antimalware service executable is undeniably relevant. This protection prevents malware attacks so you can feel safe while using your Windows 10 computer.

If you try to make antimalware service executable consume less CPU with the 2 methods explained in this article and there seems to be no progress, you should try to disable your Windows Security program permanently.

But make sure you get another antivirus program so your computer won't be at the mercy of attacks.

Thank you for reading.