Messenger (formerly MSN Messenger Service,.NET Messenger Service and Windows Live Messenger Service) was an instant messaging and presence system developed by Microsoft in 1999 for use with its MSN Messenger software. It was used by instant messaging clients including Windows 8, Windows Live Messenger, Microsoft Messenger for Mac, Outlook.com …

Messenger service is a network-based system notification Windows service by Microsoft that was included in some earlier versions of Microsoft Windows.. This retired technology, although it has a similar name, is not related in any way to the later, Internet-based Microsoft Messenger service for instant messaging or to Windows Messenger and Windows Live Messenger …