How to Fix High CPU Usage By Antimalware Service Executable

Find that the ‘Antimalware Service Executable’ program is consuming high CPU usage?

Protecting yourself against malware and virus infections should be one of your biggest priorities while you continue to use and browse the interwebs. Getting infected by malware on your computer can range from consequences like getting a low PC to experiencing regular blue screens.

The bottom line is that it’s incredibly bad to be infected by malware. Ideally here at Saint, we’d recommend that you keep this service running at all times, and here is why. However, we understand the frustration of operating with a slower laptop because of CPU-intensive background processes like this.

So to help solve your problem we’ve compiled a list of all the methods and steps you can take to fix and lessen the high CPU usage by Antimalware Service Executable on your Windows 10 PC.

Here’s how you can get started.

1. Schedule Your Scans Efficiently.

Most users suffer from a laggy computer because Windows Defender is initiating an extensive scan in the background. This can be extremely troublesome because scans, in general, are resource and CPU-intensive.

To make sure that your PC is functioning well, Microsoft programmed Windows Defender to initiate scans at scheduled intervals. This assures that your files are always maintained and uncorrupted.

Luckily, the developers also included a feature where users can schedule when the scans take place. This can help you avoid having a scan run in your background whilst you’re working or playing games.

Here’s how you can reschedule your scans:

  1. Go ahead and open the Start menu and type ‘Task Scheduler’. Click on the first app that’s returned from the query.
  2. Now, on the left pane navigate to Task Scheduler Library > Microsoft > Windows > Windows Defender.
  3. Once you’ve opened the Windows Defender folder, double-click on Windows Defender Scheduled Scan. If the texts are cut short, simply drag the line between Name and Status to the left to expand the column.
  4. Then, navigate to the Conditions tab and uncheck all the options listed below. This will clear your scheduled scans.

Task scheduler

You can end here and click ‘OK’ to finish disabling the automated scans if you want. This will turn off any automatically scheduled scans in the future. But here at Saint, we recommend that you schedule a weekly scan for your safety or at least manually scan your system at your discretion every week.

  1. To reschedule your scans, go to the Triggers tab and click on ‘New…’.
  2. Next, set up the scan to your preference. We recommend scanning at least every week. Make sure to schedule this on hours where you aren’t doing much on your PC/computer.
  3. Finally, repeat the process for the three remaining services found in the Windows Defender folder.

With all of that done, any resource-intensive scans should now be scheduled to initiate on downtime hours when you aren’t doing much on your PC.

2. Exclude Windows Defender From Itself.

Windows Defender does such an extensive scan through your system that it even scans itself. Although this is a good practice to go combat against malware that directly targets your Microsoft antivirus, there are cases when scanning itself results in a bug.

Although it’s good to be safe, you can always exclude Windows Defender from scanning itself to free up some CPU usage.

Here’s how you can exclude Windows Defender from scanning itself:

  1. First, open the Start menu.
  2. Now, type in ‘defender’ and open the first app that is returned from the search query. This should open Windows Security.
  3. Next, click on Virus & threat protection which is indicated by the shield icon.
  4. After that, navigate to Virus & threat protection settings and click on Manage settings.

Virus and threat protection

  1. Scroll down to Exclusions and click Add or remove exclusions.
  2. Then, select Add an exclusion. This will open a drop-down menu, select Process.
  3. Finally, a prompt should appear with a text field. Type ‘MsMpEng.exe’ and click Add.

After these steps, Windows Defender should no longer scan through its own directory for viruses. This should free your CPU from the related tasks.

3. Disable Windows Defender.

An unconventional fix, disabling Windows Defender will subsequently disable Antimalware Service Executable entirely. Although we don’t recommend this because of how important an antivirus software is to your computer, there are ways to go around it.

Windows Defender offers a ‘Real-time protection’ feature that enables Defender to actively protect you from any threats. This includes opening any folders, running programs, and suspicious internet activity. Since this feature happens in real-time it can be taxing on your CPU to constantly monitor your files. Disabling this will turn it off but only temporarily.

The only permanent way to disable Windows Defender is by installing a third-party antivirus software. Windows Defender only fully disables itself once it feels like you’re being protected by another antivirus program. This is why disabling ‘Real-time protection’ only lasts temporarily as Windows Defender will automatically reactivate itself.

If you want to disable the default Microsoft antivirus for good, try looking through the internet for a third-party antivirus software that isn’t as resource-intensive as Windows Defender. Despite replacing it, we do recommend manually using Windows Defender for performing ‘Full System’ scans should a need arise.

4. Initiate a Full System Scan.

This may be very unlikely but on the off chance that a virus is sabotaging your Antimalware Service, performing a ‘Full System’ scan should rid of any viruses causing this issue. Besides being helpful for your computer, ‘Full System’ scans are a great way to fix errors you weren’t even aware of.

These types of scans clear through your entire computer, including the operating system. This is precisely why it’s recommended that you perform weekly scans on your computer.

This method can take a few minutes to an hour depending on the size of your hard drive and if you’re using an HDD or an SSD.

Here’s how you can initiate a ‘Full System Scan’:

  1. Go ahead and open the Start menu.
  2. Now, search for ‘defender’ and click on the Windows Security program.
  3. Then, click on Virus & threat protection which is indicated by the shield icon.
  4. Before you initiate a scan, go to Scan options and click on Full scan.

high cpu usage by antimalware service executable

  1. Next, scroll down and click Scan now to initiate a full system scan.
  2. Finally, once your scan is complete, go ahead and see how many threats were found. Restart your computer afterward.

The full system scan should rid your computer of any malware that’s sabotaging your performance. If the scan could not find any malware, then go ahead and proceed to the last two methods.

5. SFC and DISM Scan.

PCs with corrupted files or sectors can sabotage your performance, including Windows Defender. Luckily, Microsoft programmed a scanning tool to help restore any corrupted Windows files and sectors right into your command terminal.

Authentic and functional files are kept in a compressed cache that Windows compares to your possibly corrupted files. Your system essentially has two copies of its operating system and default settings, one that you use and the other for maintenance like these scans. SFC scans will fix your files through this process, and DISM scans will compare and fix larger sectors of your system.

Here’s how you can initiate an SFC scan:

  1. First, open your Start menu.
  2. Search for ‘cmd’ and right-click the app that appears in your search query. Select Run as administrator.
  3. Now, type in ‘sfc /scannow’ and press Enter.

high cpu usage by antimalware service executable

  1. The scan should take around five minutes, depending on the hardware of your system. After the scan is complete, exit the cmd terminal and restart your PC.

Hopefully, with all the corrupted files in your operating system cleaned and replaced, your Windows key should work as intended again.

Alternatively, here’s how you can use the DISM tool to fix your problem:

  1. First, open your Start menu.
  2. Search for ‘cmd’ and right-click the app that appears in your search query. Select Run as administrator.
  3. Then, type in ‘DISM /Online /Cleanup-Image /RestoreHealth’ and press Enter.

high cpu usage by antimalware service executable

  1. Finally, wait for the scan to finish. If you notice that the DISM is stuck at a certain percentage, don’t worry as this is perfectly normal. Once the scan is finished, go ahead and restart your computer.

Now that you’ve done both SFC and DISM scans any software malfunction from Windows related to your problem should be fixed. If you feel like DISM has fixed your SFC scan tool as well, feel free to perform another SFC scan after rebooting your computer (The DISM tool can fix your SFC tool if it is corrupted).

6. Reformat Your Computer.

If you’re completely out of hope, then you can always do this final method.

Reformatting your computer will wipe out all of your settings and apps while keeping your personal files. This will guarantee that your computer starts fresh, with software fresh like a new laptop.

Please note that this method will arguably take the longest time. Windows will essentially reinstall itself into your PC and can take minutes to hours depending on your hardware capabilities.

In Windows 10, reformatting is an easier task and can be done with just the following steps:

  1. First, open the Start menu and search for ‘update’.
  2. Once opened, navigate to the left pane and click on Recovery.
  3. Then, under Reset this PC, click on Get Started.
  4. A prompt should open regarding your files. Click Keep my files and follow the prompt until your computer is finally reformatted.

high cpu usage by antimalware service executable

  1. Your computer should perform a reset on its own, go through your necessary preferences, and set up your computer like before.

Now your computer should be completely restored to its factory settings while still storing all your personal files in its storage.

If your computer performance is still suffering from the Antimalware Service Executable, then your biggest bet is to keep disabling it whenever you need to or installing another antivirus.

That brings us to the end of this article. We hope that this guide helped provide solutions that helped fix your ‘High CPU usage Antimalware Service Executable’ issue. If you have other questions related to this article or if you came across another alternative solution, feel free to share it below.

If this guide helped you, please share it. 🙂


  • Mako Young

    Mako is a staff writer at Saint. He's been writing about tech for more than a decade. When he isn't reading about the latest news on Apple, he's busy studying cybersecurity, cryptocurrency, cloud computing, and other IT-related sectors. His exceptional work graces technology and Apple-related blogs like How-To Geek,, Macgasm, onMac, PhotoWorkout, GameRant, and many more. He also has a Bachelors in Computer Science and has been writing since 2018, with over 400 posts published. LinkedIn X (Twitter)

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