An integrated threat protection solution designed to detect, investigate, and respond to cyber threats across Microsoft 365 services.
Dear Andrew Price3,
Welcome to Microsoft Community.
We understand that you want to install Microsoft Defender on your device.
According to your description, when you install Defender on your device, it shows that you need to contact the administrator.
Regarding the corresponding license information when installing Microsoft Defender, I need to explain it to you:
Usually, installing Microsoft Defender requires at least a Microsoft 365 Personal or Family subscription license. If you do not have the corresponding subscription or the subscription license information version is enterprise or other, the information displayed during installation will be different.
Installing Microsoft Defender - Microsoft Support
Need to confirm with you:
Do you have the corresponding Office product license under your account? What is your product subscription type? Microsoft 365 Personal or other?
You can log in to your Microsoft dashboard: Microsoft account | Sign In or Create Your Account Today – Microsoft and view specific product editions under Services & Subscriptions.
At the same time, you can also share with us the error messages that occurred during your installation, and we will help you further confirm the information.
Best Regards,
Zenobia.Z | Microsoft Community Support Specialist