Technically, to stop Windows Defender from running, you need to have a proper antivirus software installed, such as Avast, Kaspersky, Norton or McAfee. Windows Defender will automatically be active when Windows 10 doesn’t find any other antivirus software running on your computer. The point here is that it’s completely normal and fine for Antimalware Service Executable process to run in the background and using up resources to keep your PC from getting infected. But, in some cases, when the scan has started, it wouldn’t stop until it’s completed. Usually, Windows Defender will perform the regular scan only when your computer is idle. If the process continuously running at high disk / CPU usage, it could mean that Windows Defender is performing a regular scan, or is updating its virus definition. After the scan is completed, it will stop using any resource until its next task.

This will cause the MsMpEng.exe process to run at high resource usage for a short while, especially when the size of the file or program is very large. When you open a program or access to a file, Windows Defender will scan the particular program or file you are about to open for malware. Why is Antimalware Service Executable causing high disk and CPU usage?

Its job is to scan the files in your computer for malwares and viruses, installing updates for Windows Defender, or anything else that has to do with Windows Defender.

Msmpeng high disk usage windows 10