Note that MSN Messenger is not the same as Windows Messenger (which is supplied with Windows XP), even though they provide very similar functionality.
Please ensure you are using version 6.2 or later of MSN Messenger, available from the MSN website.
To setup your DrayTek Vigor router to use MSN Messenger or Windows Messenger, go to the Applications>>UPnP configuration menu and select “Enable UPnP Service”
If you are using Zone Alarm, you may have to stop Zone Alarm.
If you are still having trouble with Windows Messenger please refer to Microsoft Knowledge Base Article 324214