Microsoft uses a Global Device ID (GDID) in Windows. This makes Windows installations uniquely identifiable, survives reboots and Windows updates, and cannot be removed. This continues to cause a stir – but it shouldn't really surprise anyone. What's actually surprising is that the GDID has now held up in court and led to the identification of a suspected perpetrator.
Fundamentally, such mechanisms are already known in Windows operating systems. For example, tinkerers notice this when they replace an SSD or a motherboard. Windows then asks for a new activation – the system's machine IDs no longer match. However, the GDID goes a step further. Microsoft also documents it, albeit somewhat hidden in references for Azure cloud systems. There, the “GlobalDeviceID” appears as a string. The description explains that it is Microsoft's Global Device Identifier, which Microsoft uses internally.
On GitHub, a user with the handle “SmtimesIWndr” has taken the trouble to gather information about the Windows GDID. It is said to be a component of Windows telemetry that is sent to Microsoft's servers along with other information. This happens regardless of whether Windows was set up with a Microsoft account or a local account.
