How to register singe device in MS Office 365?

Question

I cannot sign in MS Office 365 from my device and i am a single user and cannot register my device. The registration fails during the process of registering device at my company

I am the company

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Moved from: Microsoft 365 and Office | Access | For business | Windows

Answer 1

Dear @Christopher Hirt,

Welcome to Microsoft Q&A. 

Thanks for the details. This message usually appears when Windows cannot complete the Microsoft Entra ID (Azure AD) device registration, which is required before Office 365 apps can sign in.

Even for single‑user tenants, the device must be allowed to register in Microsoft Entra ID.

To get this working, please check these items:

1/ Make sure your account is the Global Administrator

Sign in at: https://admin.microsoft.com

If you cannot open the Admin Center, this indicates the tenant admin permissions may not be active on your account.

2/ Allow devices to join or register in Entra ID

Go to: Microsoft Entra admin center > Devices > Device settings

Confirm these two settings:

1. Users may join devices to Microsoft Entra
2. Users may register their devices with Microsoft Entra = All If these are set to None, device registration will always fail.

3/ Re-register the device manually

On Windows device, go to Settings > Accounts > Access work or school

Disconnect (if any old entries exist) then Restart the PC

Add work account again, then sign in to Office 365 apps.

Device registration does not work on Windows Home. Windows Pro / Enterprise is required.

If you can share the exact message you see (or whether you can open admin.microsoft.com), I can help pinpoint the cause more precisely.

I hope this information helps point you in the right direction. If you run into any issues while trying the steps, or if something still doesn’t feel quite right, please don’t hesitate to reach out again. I’ll do my best to support you however I can.  

Looking forward to hearing back from you with any updates or additional details. 

Warm regards, 

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Answer 2

To register a single device in Microsoft 365, follow these steps:

1. Check Device Enrollment: Ensure that your device is enrolled in Mobile Device Management (MDM). You can verify this by checking the Tenant Details section using the dsregcmd command.
2. Join Microsoft Entra ID: If your device is not enrolled, go to Settings > Accounts > Access work or school, select Connect, and follow the steps to join your device to Microsoft Entra ID.
3. Sign In: After joining, sign in to your device using your Microsoft 365 credentials. You may need to restart your device after this step.
4. Troubleshoot Registration Issues: If you encounter issues during registration, consider running the Microsoft 365 sign-in troubleshooter to diagnose and resolve any problems.
5. Admin Assistance: If you are unable to register the device yourself, you may need to contact your Microsoft 365 admin for assistance, as some settings may require admin privileges to change.
6. Re-register Device: If your device has been previously registered and is now disabled, you may need to disconnect and reconnect it. Go to Settings > Accounts > Access work or school, select your account, and choose Disconnect. Then, reconnect by selecting Connect and signing in again.

By following these steps, you should be able to register your device successfully for Microsoft 365 access.