Windows Chicago was the development codename used by Microsoft during the early 1990s while building the successor to Windows 3.1, which eventually shipped as Windows 95. Its system sounds came from that beta period, so they differ slightly from the final release chimes most people remember. Clips pairing the start and shutdown tones later circulated in operating system history videos, startup compilations, and meme edits, where the unfamiliar but clearly Windows-like chimes work as a shorthand for booting up, logging off, and retro computing culture.