Microsoft's Windows XP, released in 2001, used a short shutdown chime as part of its built-in system sounds, a sound millions of people heard daily as they switched off home and school computers. As XP was replaced by newer versions of Windows, the chime survived online in nostalgia compilations, retro computing videos and meme edits, where it now works as shorthand for the early 2000s. Its calm, final tone makes it instantly recognisable even to people who never used the system themselves.