Windows 10 was released by Microsoft in 2015, and its built-in system sounds included a distinct chime for messaging notifications. The sound became familiar to millions of PC users through everyday use in Mail, messaging and other Windows apps, rather than through a single viral moment. As Windows 10 remained widely used for years, the chime became shorthand online for a new message arriving, and creators now reuse it in videos and streams to instantly signal a notification without needing on-screen text.