This "MsMpEng.exe" seems to run and use most of my disk resources.

Hello, Omnishura,

The Windows Defender program is granting Real Time Protection which means that the antimalware software should scan everything that you do on your Windows 10 system. Additionally it will also perform a full scan – all your files and data will be verified. During this full scan the antivirus will require more resources than usual and that’s when you might experience the high CPU usage issue. Of course, if the scan runs it’s recommended to let the program do its job – do note that depending on the amount of files this scan can run between a few minutes and a few hours.

Adjust the Windows Defender Schedule

1. Power-on your computer and from Desktop press the Win+R keyboard keys.
2. The Search box will be displayed; there type: taskschd.msc. Click OK when done.
3. From Task Scheduler double-click on the Task Scheduler Library; from the expanded menu pick Microsoft and then click on Windows.
4. Scroll down until you find the Windows Defender entry. Click on it.
5. From the main panel of the window double-click on Windows Defender Scheduled Scan.
6. From the window that will be displayed switch to General tab and uncheck the Run with highest privileges option.
7. Then, switch to Conditions tab and just uncheck all the checkboxes that are displayed under this tab.
8. Save all these settings.-Windows Report