If you are having problems signing into Windows Live Messenger, you might need to add the program (MSNmsgr.exe) to your firewall exceptions list. If that doesn’t help, you might need to check the Microsoft .NET Messenger Service status, which is the online service provided by Microsoft that makes it possible for you to use Windows Live Messenger or MSN Messenger. Microsoft is continually updating Windows Messenger with new functionality. When a software update is available, Windows Live Messenger displays a message, where you can download and install the upgrade.