GUID (Globally Unique Identifier) - What it is and where you will see it

Globally Unique Identifier (GUID)

What it is

A GUID is a 128-bit ID that’s designed to be unique. It looks like a long string of letters and numbers with hyphens, for example 550e8400-e29b-41d4-a716-446655440000. Windows and many apps use GUIDs to tag things so they can tell them apart every time.

Where you will see it

  • Windows components, registry keys, COM objects, and drivers

  • Software installers, license and device IDs

  • Logs, crash reports, and configuration files

Why it matters

GUIDs keep systems organized and reduce mix-ups between files or settings. They are not passwords and not personal data by themselves, but sharing raw logs with GUIDs can reveal internal structure or aid targeted troubleshooting, so treat them like technical details you only share when needed.

Quick notes

  • “GUID” in Microsoft land is the same idea as a UUID elsewhere

  • Format is typically 8-4-4-4-12 hexadecimal characters

  • They are practically unique for real-world use cases

    Glossary (A–Z)

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