Where our keys come from
It's a fair question when a key costs a fraction of Microsoft's price. Here's the straight answer.
The short answer
Our keys come from unused and retired computers. When companies replace their PCs, or computers are taken out of service, the Windows and Office licenses bought for them often go unused. Those are the keys we sell.
They are all retail licenses, the same kind sold in a box or in the Microsoft Store. Microsoft's license terms let you move a retail license to another PC, which you can't do with the OEM licenses that come preinstalled on a computer.
Every key is a genuine Microsoft product key. You type it into Windows or Office and it activates through Microsoft's own activation servers, exactly like a key bought anywhere else.
Why they cost less than at Microsoft
Microsoft sells new licenses at full list price: Windows 11 Pro is $199.99 in the US Microsoft Store. The keys we sell were already paid for once and are no longer in use, so we can offer them for much less. The software is the same: the same Windows or Office, with the same updates from Microsoft.
What we don't sell
- No activators, cracks or "KMS" tools. You get a product key and nothing to run on your PC.
- No public generic keys. Those only install Windows and never activate it (more on generic keys).
- No shared accounts. The key is sent to you only.
If a key doesn't work
Once in a while, a key fails to activate. If that happens, contact us: we send you a replacement, and if we can't, you get a full refund within 30 days. See our refund policy.
Check it yourself
After you enter your key, open Settings, then System, then Activation. "Windows is activated" means you're done. Our guide on checking Windows activation explains each message you might see.
Good to know
SOS License is an independent reseller. We are not affiliated with Microsoft Corporation and we are not a Microsoft partner. Microsoft, Windows and Office are trademarks of Microsoft Corporation.