Microsoft introduced this startup sound with Windows 7 in 2009, replacing the louder XP chime with a softer, ambient four-note melody designed to feel welcoming. It quickly became one of the most recognisable sounds of the era as Windows 7 ran on hundreds of millions of PCs through the early 2010s. Online it spread through remix culture, slowed-and-reverbed versions, and endless parody mashups, and today it survives as shorthand for old-school computing nostalgia in memes and video intros.