Alex Ruben
How To Resolve High CPU Usage Caused by Windows 10 Antimalware Service Executable
If your PC is feeling slower than usual or your fan’s constantly running, there’s a good chance that Windows Defender’s Antimalware Service Executable is hogging resources. It’s kind of weird, but that service is responsible for real-time protection, scanning files, and generally keeping your system safe. On some setups, it seems like it uses way more CPU than it should, especially when doing heavy scans or checking for updates. Luckily, you don’t have to turn it off completely—there are a few tricks to keep it from running wild, while still staying protected. This guide aims to help you tame things down, so your PC stays responsive and your CPU isn’t sweating bullets all day long.
How to Lower Windows Defender Its CPU Load in Windows 11/10
Method 1: Adjust Scheduled Scan Timings and Settings
This one’s useful because that scheduled scan is often set to run when you’re actually trying to do work. Opening the Task Scheduler allows you to tweak exactly when Defender runs its scans, or disable some triggers that cause unnecessary CPU spikes.
- Click the Start menu, type
Task Schedulerand hit Enter. - Navigate to Task Scheduler Library > Microsoft > Windows > Windows Defender.
- Find the task named Windows Defender Scheduled Scan, right-click, and select Properties.
- In the General tab, gotta uncheck Run with highest privileges. Seems pointless or maybe even harmful here, and might cause some scans to run in the background with more priority.
- Go to the Conditions tab. Uncheck options like Start the task only if the computer is idle. This setting can cause the scan to run immediately when your PC is busy, which isn’t great for CPU use. Disabling it stops the scan from kicking in during prime work hours.
- Finally, go to the Triggers tab and set scans for late at night or early morning, so they don’t interfere with your work. If you don’t use scheduled scans, you can even disable this task altogether by right-clicking and choosing Disable.
This approach helps because it avoids interrupting your workflow, which is when Defender usually jumps into high gear. Expect your CPU to chill out during the day, but scans still run overnight.
Method 2: Limit CPU Power to Defender via Group Policy
There’s a way to set a cap on how much CPU Defender can use during scans, and it’s kinda unintuitive, but it works. You’ll need to open the Local Group Policy Editor. This doesn’t work on Windows Home unless you enable it via registry or third-party tools, so skip this if that’s your case.
- Press Windows + R, type
gpedit.mscand press Enter. - Within the editor, go to Computer Configuration > Administrative Templates > Windows Components > Microsoft Defender Antivirus > Scan.
- Look for Specify the maximum percentage of CPU usage during a scan. On some versions, this setting might be missing, as Microsoft doesn’t always include it by default.
- If you find it (or install a custom policy pack), double-click, set to Enabled, then pick a lower percentage like 30% or less. This caps Defender’s CPU usage during scans, preventing it from taking over your whole system.
Why does this help? Because it directly limits the resource hogging during scans. The tradeoff: scans might take longer, but your PC stays more responsive. On some setups, this setting isn’t available or doesn’t stick, so don’t be surprised if it doesn’t work perfectly everywhere.
Method 3: Add Defender Directory to Exclusions
Another thing that kinda bugs Windows Defender is that it scans its own files, which just wastes CPU. Adding Windows Defender’s folder to the exclusions list prevents that simping from happening, and, honestly, reduces redundant scans.
- Open Windows Security from the Start menu.
- Go to Virus & threat protection.
- Click on Manage settings.
- Scroll down to Exclusions and select Add or remove exclusions.
- Click on Add an exclusion, choose Folder, and navigate to:
C:\Program Files\Windows Defender.
Honestly, this is a bit of a workaround, but it can shave off some CPU cycles because Defender isn’t wasting resources re-scanning its core files. Just be cautious with exclusions, since you don’t want to accidentally skip other important files.
Extra Tips & Troubleshooting
If the CPU spike persists or you want to double-check everything, here’s what else can help:
- Regularly check for Windows Updates. Sometimes Microsoft addresses resource issues in patches.
- On some machines, disabling other heavy apps during scans can help. Or better yet, set scans when you’re not actively using the machine.
- Use Task Manager (Ctrl + Shift + Esc) to see what else is hogging CPU or RAM — maybe other background processes are the real culprits.
Wrap-up
These tweaks shouldn’t kill Windows Defender but help keep it from turning your PC into a fan-firing mess. It’s all about finding a balance—keeping your system secure without sacrificing responsiveness. Not every trick works perfectly on every setup, but collectively, they usually make a noticeable difference. Just keep an eye on CPU usage after changes to see what’s helping most, and adjust accordingly.
Frequently Asked Questions
What is the Antimalware Service Executable?
This is basically the core Windows Defender process that handles scanning for malware. It runs in the background and sometimes, especially during scans or updates, can max out CPU.
Does limiting CPU usage affect scan effectiveness?
Kind of. The scans might take longer, but they still find threats. It’s a tradeoff — slower scans, less CPU stress, and a more responsive machine while it runs.
Is disabling Windows Defender a good idea?
Not really. It’s your main security tool unless you’re running a third-party antivirus. Instead, tuning it down or scheduling its scans during off-hours is smarter. Of course, without protection, your system is vulnerable, so be cautious.
- Hopefully, these tips help keep your PC running without turning into a fan heater.
- Just something that worked on a few setups, so give it a go and see what sticks.