MSN Messenger, Microsoft's instant messaging service, was one of the most popular ways to chat online during the 2000s before it was eventually replaced by Skype. Its short notification sounds became part of everyday computer use, signalling new messages, contacts signing in and nudges between friends. As the service faded, the sounds lived on in memes, reaction videos and nostalgia edits, where a single chime can instantly place a scene in that era. Today it works less as a functional alert and more as a cultural reference to early social internet life.