Fix Windows 11 high resource usage from antimalware service

Many Windows 11 users experience system slowdowns when the antimalware service executable consumes excessive CPU, memory, or disk resources. This background process, which powers Windows Defender, can significantly impact system performance. Here are proven solutions to address this issue while maintaining system security.

The antimalware service executable (MsMpEng.exe) runs Windows Defender’s core functions, providing essential protection against malware threats. When this service becomes resource-intensive, it can make your system sluggish and less responsive.

Method 1: Optimize Windows Defender scan schedule

Rescheduling Windows Defender scans to run during idle hours effectively reduces resource consumption without compromising security.

  1. Search for “Task Scheduler” in the Start menu and launch the application.

  1. Navigate through Task Scheduler Library > Microsoft > Windows in the left panel.

  1. Find and select the Windows Defender folder.

  1. Right-click “Windows Defender Scheduled Scan” and select Properties.

  1. Access the Triggers tab and click New.

  1. Set up a weekly schedule during your system’s typical idle time.

Method 2: Disable real-time protection temporarily

This approach provides immediate relief from high resource usage but should be used cautiously.

  1. Open Windows Security from the Start menu.

  1. Select Virus & threat protection.

  1. Click Manage settings.

  1. Toggle Real-time protection to Off.

Method 3: Stop Windows Defender service

For systems with alternative antivirus protection:

  1. Launch Services from the Start menu.

  1. Locate Windows Defender Antivirus Service and click Stop.

Method 4: Registry modification

This method permanently disables Windows Defender but requires careful implementation:

  1. Open Registry Editor from the Start menu.

  1. Navigate to: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows Defender

  1. Create a DWORD value named DisableAntiSpyware.

  1. Set the value to 1 and restart your computer.