How to Find the Product Key Already on Your PC
Published 10 Sep 2026, updated 18 Sep 2026
Many PCs already carry a Windows license. Before buying a key, it's worth checking what you have.
Keys embedded in the firmware
Most laptops and prebuilt desktops sold with Windows store an OEM key in the motherboard's firmware. Windows Setup reads it automatically and activates the matching edition without asking. To view it, open Terminal and run:
(Get-CimInstance -ClassName SoftwareLicensingService).OA3xOriginalProductKey
If it returns a key, your PC has a firmware license for the edition it shipped with, usually Home. If it returns nothing, there's no embedded key; that's normal for self-built PCs.
The installed key
Windows doesn't display the full installed key in Settings. The command slmgr /dli shows the last five characters and the license channel (Retail, OEM or Volume), which is enough to match it against a key you have on record.
Digital licenses without a key
If the PC was upgraded for free from Windows 10, or activated through Microsoft Store, it may have a digital license instead of a key you can see. That's fine: reinstall the same edition and it reactivates on its own. Settings › System › Activation shows "activated with a digital license" in that case.
When you do need a new key
- A self-built PC with no license.
- Upgrading from Home to Pro. See how.
- A new motherboard where the old license was OEM. Hardware changes explained.
Third-party "key finder" tools are unnecessary for any of this, and some bundle unwanted software. The built-in commands above are safer.
