This bug has been present since the first release. I've reported it to ESET before and been promised it would be resolved in future versions... But it never has been. Why not? The ESET installer is trying to install EMSX when the Exchange Transport Engine is still running. That's the problem. Even with the latest 10019 build. I have to manually stop the Exchange Transport Engine before installing EMSX. Why can't EMSX do this?