The message clearly says that a required Windows Service could not be started. Here are the areas you need to take a look at to fix this Microsoft Defender error: Check Windows Defender service status ...

To fix high memory usage by Antimalware Service Executable on Windows 11, try turning off real-time protection, uninstalling pirated apps, scanning for malware, rescheduling Windows Defender scans, or ...

Windows Defender Antivirus or also called Windows Defender Security Center is a built-in antivirus program of Windows. A program that gives real-time protection of your computer against threats such ...

Windows Defender or Windows Security gets its regular updates through Windows Updates. However, if, for some reason, the definition update is not able to proceed as expected, then you can try a couple ...