Pour a cup of cocoa and settle down for another episode of Microsoft Storytime. Why do codenames sometimes linger on in the implementation of products?

"Chicago" was Microsoft's codename for Windows 95. During its development, Microsoft's new operating system went by several names externally – Windows 4.0 and Windows 93, to name but two – but internally, it was named for the windy city.

The successor to Windows 3.x debuted 29 years ago as Windows 95, but during its development, engineers needed a name – not least for drivers. And so, lurking in the Signature entry of .INF files was $Chicago$.

The entry indicates the operating systems for which the INF is valid, and could also be $Windows NT$. As far as Microsoft was concerned, both values meant "All Windows operating systems." But why $Chicago$?