The software company plans to shut down WLM by March next year worldwide except for China, and replace it with Skype which it purchased 18 months ago
Microsoft is to replace its instant message chat tool, Windows Live Messenger (WLM), with Skype.
The software company acquired Skype last year for $8.5 billion (£5.3 billion).
Microsoft says WLM, which used to be known as MSN messenger, will be turned off by March 2013 everywhere except in China.
In 2009, Microsoft said WLM had 330 million users, but recent reports suggest this had fallen to 8.3 million, a 48 per cent year-on-year drop.
Microsoft is offering a tool to migrate WLM messenger contacts over to Skype, to prevent users going to rival platforms such as WhatsApp or Google Talk.