Can not register a Windows device under my Microsoft account

If you are having trouble registering your Windows device under your Microsoft account, there are a few steps you can take to troubleshoot the issue:

1. Check the Device Type: Ensure that the device you are trying to register is not already classified as a Microsoft Entra registered device (also known as "workplace joined") or an Intune MDM-only enrollment device. These types of devices cannot be registered as Windows Autopilot devices.
2. Verify Hardware Hash: If you are manually registering the device, make sure that the hardware hash is correctly obtained and formatted. You can check the manufacturer and serial number using PowerShell:

      Get-CimInstance Win32_BaseBoard | Select-Object Manufacturer, SerialNumber
   

3. Check for Existing Registrations: If you receive an error indicating that the device is already registered, verify if the device is listed in the Windows Autopilot devices pane in Intune. If it is, you may not need to register it again.
4. Remove Previous Registrations: If the device is already registered under a different tenant or as a different type, you will need to deregister it from Microsoft Intune and Microsoft Entra ID before attempting to register it again.
5. Retry Registration: After ensuring that the device is not registered elsewhere and that you have the correct hardware hash, try registering the device again.

If these steps do not resolve the issue, consider reaching out to Microsoft support for further assistance.

Hello Penbury,

Welcome to Microsoft Q&A forum. It's my pleasure to help you today.

I understand that you are struggling with register a device to your Microsoft account. Before we proceed, I'd like to ask a few questions to understand your situation better:

• May I know the type of device you're trying to add. The add Serial number feature is usually for Microsoft Hardware Product.
• May I know what it says when you try to add your device?

I'm waiting for your reply so we can work on it together.