how to activate window 10 on my pc

Windows 10 requires either a valid digital license or a genuine 25-character product key; if this PC has neither, you must purchase a license rather than obtain a free key.

1. Check whether you already own a license

Go to Start → Settings → Update & Security → Activation and review the activation message.

• Previously activated on this PC: Connect to the internet and sign in with the Microsoft account associated with the license. A digital license does not require you to locate or enter a product key.^1^
• Windows came preinstalled: Check the PC packaging and its Certificate of Authenticity. The key may also be preinstalled in the device firmware.
• Retail boxed copy: Find the key on the label inside the box.
• Digital purchase from a retailer: Check the purchase email or the retailer’s digital locker.
• Microsoft Store purchase: Check the Microsoft account and email address used for that purchase; it may use a digital license instead of a visible key.^1^
• Refurbished PC: The refurbisher is responsible for supplying the product key.

If Windows was factory-installed, you can check for a firmware-embedded OEM key by opening Command Prompt as administrator and running:

wmic path SoftwareLicensingService get OA3xOriginalProductKey

If a 25-character key appears, keep it private; do not post it publicly.^2^

2. Activate with an existing key

Open:

Start → Settings → Update & Security → Activation → Change product key

Enter the 25-character key and complete activation while connected to the internet.^3^

The installed edition must match the license—for example, a Windows Home license does not activate Windows Pro. Check the installed edition on the Activation page before purchasing or reinstalling anything.

3. If you have no license

In Start → Settings → Update & Security → Activation, select Go to Store and follow the Microsoft Store instructions to purchase a digital license.^1^

Avoid cheap keys from unknown websites, activation scripts, cracks, and KMS activators. They may be unauthorized volume-license keys and can stop activating later.

Consider Windows 11 before purchasing

Windows 10 reached end of support on October 14, 2025 and no longer receives standard security updates, feature updates, or technical assistance. Before buying a Windows 10 license, check Start → Settings → Update & Security → Windows Update → Check for updates to see whether the PC is eligible for Windows 11. If it is not eligible, Microsoft’s supported alternatives include Windows 10 Consumer Extended Security Updates or replacing the device with one that supports Windows 11.^4^

References

1. [Windows 10](https://support.microsoft.com/windows/activation/activate-windows#in-windows-10,-what-windows-activation-method-do-i-use,-a-digital-license-or-a-product-key)
2. I couldn't reactivate windows10 again - Microsoft Q&A
3. [Windows 10](https://support.microsoft.com/windows/activation/reactivating-windows-after-a-hardware-change#if-you-don't-have-a-digital-license,-enter-your-product-key)
4. Windows 10 support has ended on October 14, 2025 | Microsoft Support