In the UWP/WinX client, the device id is created using the [https://docs.microsoft.com/en-us/uwp/api/windows.system.profile.hardwareidentification.getpackagespecifictoken ASHWID identifier] encoded to a Base64 string. (<= 3.7.X)
The [https://docs.microsoft.com/en-us/uwp/api/windows.system.profile.systemidentification?view=winrt-19041 SystemIdentification.GetSystemIdForPublisher() ]Method returns a unique system identifier based on the app publisher ID
The ID is generated either using a Trusted Platform Module (TPM), if present, or a Unified Extensible Firmware Interface (UEFI) if present
If neither of these sources is available, this method will return an ID that is backed by the Windows registry.