It depends on the operating system used and whether your device is onboarded to Defender for Endpoint. 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. Microsoft Defender for Endpoint Plans 1 and 2.