An FYI on the Messenger Service:
This Service is designed for the Administrator of a Network to communicate with the other system on the Network. It IS a legitimate Service.
However, it is unethically usedusually to trick a user into clicking on something to "fix" what is suppose to be a problem and is intentionally configured to appear it is a Microsoft Windows 'warning'.
Disabling it and stopping the Service does no harm to your computer.