Windows 7 was released by Microsoft in 2009, and its system sounds became familiar to millions of people who used the operating system at home, school and work. The warning chime was designed as a short, polite alert for errors and notifications, rather than a harsh alarm. As Windows 7 was replaced by newer versions, the sound took on a nostalgic quality and began appearing in YouTube videos, edits and memes as a quick signal for a mistake. Creators still use this error sound because it is instantly recognisable, light and easy to place over almost any clip.