Hi Mr. Kim Ho Wesley Chan,
Based on the symptoms, the device is most likely being forced into Microsoft Entra ID enrollment with automatic MDM enrollment during OOBE. The error "Registering your device for mobile management (5, 0x80070715)" occurs during the MDM enrollment phase, which is commonly triggered by Intune auto-enrollment policies or an Autopilot deployment profile assigned to the device.
If the device is registered in Windows Autopilot, simply resetting Windows will not help because OOBE will download the Autopilot profile again and return to the same enrollment screen. The device must be removed from the Autopilot service before it can be configured as a standard personal PC.
The first thing to verify is whether the device exists in Microsoft Entra Admin Center > Devices and Microsoft Intune Admin Center > Devices > Windows Autopilot devices. If you cannot access the Intune portal because the tenant does not have an active Intune license, you may need a Global Administrator to obtain temporary licensing or open a Microsoft support case to verify the Autopilot registration.
If the notebook was purchased new from an OEM or reseller, I would also contact the seller and provide the device serial number. Many Autopilot registration issues occur because the hardware was previously uploaded to an organization's Autopilot tenant and was never deregistered. Only the tenant that owns the Autopilot record can remove it.
Once the device has been removed from Autopilot and any Entra/Intune enrollment records have been deleted, you can perform a factory reset or reinstall Windows 11. OOBE should then present the normal personal setup flow instead of forcing organizational enrollment. Until the Autopilot or enrollment association is removed, the device will likely continue returning to the same screen regardless of how many times Windows is reset.
Harry.