Microsoft has run a month-long teaser for Windows 1, which has probably been associated with third-party Netflix's Stranger Things for a long time. You can find the trailer videos in the Microsoft Store.
The description reads:
Experience nostalgia from 1985 with a special-edition Windows 10 PC app inspired by Windows 1.0 – but one that was taken over from the upside down by Stranger Things. Explore the secrets and secrets that haunt Hawkins, unlock unique show content and Easter eggs, and play retro games and puzzles – all based on Stranger Things 3. Help Eleven, Steve, Dustin and Gang save Hawkins and the world. Embrace the 80's and grab your hairspray, because it's basically the most radical show-companion experience ever. But fair warning: beware of the Mind Flayer. Download the Windows 1.11 app today. Good luck!
Unlike Windows 1, which fits on some floppy disks, Windows 1.11 is a download of 775 MB and is currently only available in the US.
Available here in the store.
Developer: Microsoft Corporation