Thread by @jensenharris

Here's some puzzle solving fun for a Friday night.

As we developed Windows, one of the minor decisions we had to make was what wallpaper to use for various internal builds.

These builds always leaked outside of Microsoft, so we knew that the wallpapers would also end up public.

Traditionally, these wallpapers included text embedded in them threatening to throw people in jail if they leaked the build, blah blah, substantial penalty for early withdrawal, not all coins go up in value (some go down!), etc. etc.

We wanted to try a more elegant tact.

So early in Windows 8, we created a wallpaper that was a combination of the text the lawyers wanted us to use with an attempt to appeal to people's better nature...

...thus the "shhh... let's not leak our hard work" series of wallpapers was born.

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.

We crafted a puzzle and embedded it in the default wallpaper. 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.

We did not expect what came next.

The first version of the wallpaper was just green with a grid of letters. The grid (as a kind of easter egg) matched the typographic grid we were building into Windows (still in use today.)

We waited for the build to leak and once it did, were excited to see what people thought.

To our surprise, many people thought it was a security feature, and worried that these letters were going to be used to track them down if they posted screenshots. (Ignoring that you could easily change the wallpaper, obscure it... and that it was the same graphic on every PC.)

Once this build leaked, we changed the wallpaper on the next set to continue revealing the puzzle.

To fuel the conspiracy theories, I used Photoshop to mess with some pixels in the grid towards the bottom of this wallpaper to represent that we had "embedded security" into it.

In reality, it was just me messing with the image.

Interestingly, the "messed with" pixels represented the single biggest dip in pirated distribution of Windows betas we ever saw, as people spent time trying to ascertain what new security technology we were using to track them.

Eventually, we got sick of the ugly green wallpaper and started using backgrounds that we had rejected from Windows 7 as the base wallpaper.

This version was, I believe, the last published version of the wallpaper and, thus, the easiest version of the puzzle to solve.

But, despite months of the grid of letters on 1000's of PCs at Microsoft and pirated to who-knows-how-many computers outside, I am aware of only one person figuring out definitively that it was a puzzle and solving it.

A dev from Ireland solved it and sent us the answer in 2011.

This is the only instance I'm aware of a puzzle being embedded into an unreleased software product... but perhaps there are others?

In the end, we thought it would be a bit of fun for everyone involved.

So... there's a walk through an esoteric piece of Windows history.

If you like puzzles, feel free to have a go at it. For a harder challenge, start with one of the green wallpapers.

I'll post the correct solution here later this weekend!