Your Windows 7 key is probably worth $0 to a reseller—but worth $139 to you. Try it during installation. If it works, you’ve saved the price of a new SSD. If it doesn’t? You’ve lost 5 minutes.

Windows 7’s final gift to you isn’t nostalgia—it’s a free ride to the modern era. Disclaimer: Microsoft can theoretically disable this behavior at any time. But as of today, it works like a charm.

Here’s the good news: The Short Answer: Yes, With a Catch Microsoft officially ended the free upgrade offer on July 29, 2016. But unofficially? The activation servers still accept Windows 7 and 8.1 keys for Windows 10. Even better, those same keys work for Windows 11.

No one has been retroactively deactivated. No license audits target individuals doing this. Don’t buy a new license yet.