Microsoft developers hid a secret puzzle in Windows backgrounds as they knew images would leak

Microsoft developers working on Windows 8 created a puzzle and embedded it in the wallpapers used for internal builds of the operating system.

The team knew that the images would leak out to the public -- and probably the internal builds of Windows -- so they decided to have some fun with it. Over the course of numerous builds, the puzzle was developed -- but only one person ever solved it!

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Over the weekend, Jensen Harris -- a former group program manager of Microsoft Office and Microsoft director leading the team working on the redesign of Windows 8 -- took to Twitter to come clean about the secret puzzle.

He explained that it was common for internal test builds of Windows to have wallpapers that were not intended for public release, but said that messages tended to be included to discourage leaking:

https://twitter.com/jensenharris/status/987544944553308160

Legal guff is never very exciting so, as Harris said: "Of course, within days builds with this wallpaper leaked and, by that time, we had figured out how to hide certain features such that even though the builds leaked, the features themselves weren't there. So, knowing that the builds would still leak, we decided to make it fun."

The idea was to serialize a puzzle within the wallpapers:

We worked out a plan to progressively reveal it leading up to the first public beta, and decided we would wait and see how long it took someone to solve it.

https://twitter.com/jensenharris/status/987544948516900864

Sure enough, the wallpaper leaked, but people seeing the puzzle thought it was a security feature that could be used to track the source of leaks. The team decided to turn the notch up a little:

https://twitter.com/jensenharris/status/987544952581210112

https://twitter.com/jensenharris/status/987544954791542785

Harris does not say how many updates there were to the puzzle, but eventually we reach this stage:

https://twitter.com/jensenharris/status/987544957148848130

https://twitter.com/jensenharris/status/987544959900250112

If you're interested in the solution to the puzzle, check out this thread started today by Harris:

https://twitter.com/jensenharris/status/988221471368474625

Did you know the puzzle at the time -- or even manage to solve it?