Your graphics card carries a unique identifier — the GPU UUID — assigned by NVIDIA or AMD. It is one of the more stable things a fingerprinting system can read, and it is worth understanding where it sits.
What the GPU UUID is
The GPU UUID is tied to the card itself. It is visible through vendor tools (such as nvidia-smi) and system APIs, and it does not change when you reinstall drivers or even reinstall Windows. For a tracker or an anti-cheat, that stability is exactly the appeal.
Can it be changed?
Honestly: not by ordinary software. The GPU UUID lives at the card's firmware and driver level, not in the Windows registry. HWIDChanger changes the identifiers that genuinely can be changed safely — Windows IDs, the disk volume serial, network adapter (MAC) addresses — and does not touch the GPU UUID. Tools that claim to rewrite it operate at firmware level (a VBIOS flash), which is risky, can brick the card and voids the warranty.
What this means in practice
For most software DRM and many game anti-cheats, changing the Windows, disk and network identifiers is enough to look like a different machine. Against a system that specifically reads the GPU UUID, a software HWID change has a real limit — and it is more honest to know that than to expect a tool to do something no safe software can.