Is it safe to buy a cheap Windows 11 key? What to check first

Retail, OEM and volume keys: what you're actually buying

Key type	Meant for	What to know
Retail	Individual buyers	One PC at a time. You can move it to a new PC after you deactivate the old one. This is what MasterKeys sells.
OEM	PC makers and system builders	Preinstalled on a new PC and tied to that machine's hardware. It doesn't move with you.
Volume (MAK or KMS)	Organizations with a Microsoft volume agreement	Belongs to that organization. KMS activation needs the company's own server and expires if the PC stops reaching it.
Generic or default keys	Installing Windows only	Microsoft publishes these so setup can install an edition. They never activate Windows. A seller who sends one hasn't sold you a license.

Why a genuine key can cost $10

Microsoft's own store price is the highest price for a license, not the only one. Independent resellers buy retail keys from distribution and sell them digitally: there's no box, no shipping and no shop rent. Prices across the market are low for the same reason. What separates a good seller from a bad one isn't the price but what happens when a key fails.

What "lifetime" means for a Windows key

• One PC at a time. A retail Windows key activates one computer. "Lifetime" means you pay once and it doesn't expire, not that it covers every device you own.
• Reinstalls are fine. Reinstalling on the same PC reactivates automatically, because the digital license is stored for that hardware.
• New hardware. After a motherboard change, sign in with the Microsoft account you linked to the license and run the Activation troubleshooter.

How to check that your key is genuine

1. Enter it in Settings › System › Activation › Change product key. Our activation guide has the full steps.
2. The status should read Windows is activated with a digital license, or linked to your Microsoft account once you sign in.
3. For a second opinion, run slmgr /xpr in Command Prompt. It should say the machine is permanently activated. A date in a few months means a KMS (volume) activation, not a retail license.

Microsoft explains activation states and error codes on its Activate Windows support page.

Warning signs of a bad seller

• You're asked to download an "activator", run a script or change system files. Genuine keys are entered in Settings, nothing else.
• One key "for unlimited PCs" or "for all your devices".
• Activation only by phone, or the key arrives with instructions to use someone else's Microsoft account.
• No refund or replacement policy, and no way to contact a person.
• No order confirmation by email.

If a key doesn't activate

At MasterKeys, a key that's rejected as invalid or already used is replaced or refunded in full if you contact us within 30 days of purchase. Send your order number and a screenshot of the error. The details are on our refund and activation guarantee page.

Windows 11 or Windows 10?

If your PC meets the Windows 11 requirements, buy Windows 11: Windows 10 no longer gets free security updates. A Windows 10 key also activates the matching Windows 11 edition on supported hardware. See Windows 10 end of support and Windows 11 Home vs Pro.