I have been able to open multiple intances of Windows Live Messenger with this registry change taken from here:
Windows Registry Editor Version 5.00 [HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Windows Live\Messenger] "MultipleInstances"=dword:00000001
The problem is that I just installed version 2011 and it is like that registry key is not taking into account anymore. As opening the program again just brings the other window on top and not another instance.
I have Windows 7 64-bit and installed this new version of MSN by Windows Update.
Does anyone know if this is a new limitation or if there is another way of doing it?