Licensing 3 min· Updated 2026-10-16
Digital License vs Product Key: How Windows Actually Stays Activated
Why your PC activates without a key after reinstall, where the digital license lives, and when you still need the 25 characters.
Since Windows 10, activation creates a digital license — a hash of your hardware stored on Microsoft's activation servers. Reinstall the same edition on the same hardware and Windows activates itself, no key needed.
How the two relate
- •Product key → creates the digital license on first activation
- •Digital license → reactivates automatically on the same hardware, forever
- •Microsoft account link → lets a Retail license survive a motherboard swap (Settings → Activation links it)
When you still need the key
- •Fresh PC or new motherboard — new hardware ID, no existing license
- •Changing editions (Home → Pro upgrade needs a Pro key)
- •OEM license on new hardware — OEM licenses never transfer, digital or not
Buyer relevance
When you buy a key, you are buying the right to create a digital license on your hardware. A Retail key creates a license you can carry forward; an OEM key creates one welded to that machine.
Check your current state anytime with slmgr /xpr (expiration — should say permanently activated) and slmgr /dli (edition + channel).
Check a key or find your license
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