How to Limit Windows Defender Max CPU Usage in Windows 10

When scanning, Windows Defender uses nearly 50 percent of your CPU power. When needed, you can set explicit limits. Follow the below steps to set the max CPU usage limit for Windows Defender.

Windows Defender is the default antivirus solution in Windows 10. It sits in the background and provides real-time protection from any kind of virus, malware, or potentially unwanted program. Occasionally, it also does an automatic scan to make sure your PC is not infected.

If you want to, you can schedule Windows Defender to scan your system.

When a virus scan is running in the background, it consumes up to 50 percent of your CPU power. Of course, if you are doing something CPU intensive, Windows Defender can throttle itself down so as not to interfere with your work.

However, from time to time Windows Defender may use higher CPU or disregard other background or foreground applications causing them to slow down. If that’s the case, you can manually set the max CPU usage limit for Windows Defender. Once set, it will not cross that limit while scanning your system. This is particularly useful for older or less powerful computers.

So, without further ado, let me show you how.

Steps to Limit Windows Defender’s Max CPU Usage

There are two methods to set the CPU limit on Windows Defender. Both are pretty easy to follow. Follow the one you are comfortable with.

1. PowerShell Method

Using PowerShell is the simplest of ways to set the Windows Defender CPU limit. All you have to do is execute a single line of command and you are done.

1. First, open the Start Menu, search for “PowerShell”, right-click on the result and select the “Run as administrator” option. This action will open the elevated PowerShell prompt.

Windows-defender-cpu-usage-limit-open-powershell

2. In the PowerShell window, execute the below command while replacing <percentage> with the actual percentage number between 10 and 100. For example, you want to limit the CPU usage to 25 percent, type “25”.

Set-MpPreference -ScanAvgCPULoadFactor <percentage>

Note: If you set the percentage as “0”, it will completely disable CPU throttling for Windows Defender causing it to use however much it wants.

You will not see any sort of confirmation but you can be rest assured that Windows Defender will limit its CPU usage according to the above command.

Windows-defender-cpu-usage-limit-execute-command

If you ever want to reset, simply execute the above command while replacing <percentage> with 50. As I told you earlier, 50 percent is the default CPU usage limit for Windows Defender.

2. Group Policy Editor Method

If you don’t like to mess with the command line, you can use the Group Policy Editor to do that same thing. Keep in mind this tool is only available in Pro and Enterprise versions. If you are using Home edition, follow the first method.

1. First, open the Start Menu, search for “gpedit.msc” and press Enter. This action will open the Group Policy Editor.

2. Now, expand the folder on the right panel and go to the “Computer Configuration → Administrative Templates → Windows Components → Windows Defender Antivirus → Scan” folder.

3. On the right panel, find and double-click on the “Specify the maximum percentage of CPU utilization during a scan” policy.

Windows-defender-cpu-usage-limit-open-policy

4. In the properties window, select “Enabled” and then enter the percentage between 10 and 100 in the Options section. Click on the “Ok” button to save changes.

Note: If you set the percentage as “0”, it will completely disable CPU throttling for Windows Defender causing it to use however much it wants.

Windows-defender-cpu-usage-limit-set-policy

5. Now, reboot Windows to make the policy apply to your system.

That is all. From now on, Windows Defender will limit its CPU usage according to the policy settings.

To reset or revert back, simply select “Disabled” or “Not Configured” in the policy properties window.

Wrapping Up

As you can see, it is pretty simple to limit Windows Defender from hogging up all the CPU power.

Hope that helps. If you are stuck or need some help, comment below and I will try to help as much as possible. If you like this article, do check out how to how to enable Windows Defender tamper protection.

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