Full writeup of the Windows GDID
Summary
The piece analyzes Windows Global Device Identifier (GDID), tracing its Minting using the MSA Device PUID, how it is registered into Microsoft's device graph, and how it surfaces in Delivery Optimization. It debunks myths about GDID being a hardware-derived 128-bit value and explains per-install persistence and the implications for privacy and security. It also covers exposure reduction steps and provides a reproducible methodology.