Team: Huntress EDR
Product: Managed Anti-Virus
Environment: MAV Management
Summary: Using Microsoft Defender with other AV
In short, "you can, but you shouldn't."
By default, in workstation versions of Windows (Pro, etc.), Microsoft Defender disables itself when a 3rd party AV is detected.
Windows Servers do not automatically disable Defender when another real-time engine is present, but it's recommended that you disable Defender in scenarios to prevent conflicts.
Please see Microsoft Defender Antivirus compatibility with other security products for more details.