
If you're using a non-Microsoft antivirus/antimalware product on your device, you might be able to run Microsoft Defender Antivirus in passive mode alongside the non-Microsoft antivirus solution. Compatibility with other antivirus products Microsoft Defender Antivirus is built into Windows, and it works with Microsoft Defender for Endpoint to provide protection on your device and in the cloud. This protection brings together machine learning, big-data analysis, in-depth threat resistance research, and the Microsoft cloud infrastructure to protect devices (or endpoints) in your organization. Microsoft Defender Antivirus is a major component of your next-generation protection in Microsoft Defender for Endpoint. Microsoft Defender Antivirus is available in Windows 10 and Windows 11, and in versions of Windows Server.


Windows Defender will not be enabled and functioning properly if there is a program other than Windows Defender listed.

Go to Security and Maintenance, look in 'Security' and see what program is listed under Virus Protection. Note the statement "If you want to use Windows Defender Antivirus, uninstall all of your other antivirus programs and Windows Defender Antivirus will automatically turn on.

In your previous threads you indicated you were using a third party antivirus program so I assume you are a "new" user of Windows Defender.
