mm_server.exe is a process belonging to Musicmatch Jukebox which organizes and plays music media such as MP3. It gives the user easy access to the Musicmatch Jukebox application and settings. This is a non-essential process.
Disabling or enabling it is down to user preference.
Non-system processes like mm_server.exe originate from software you installed on your system. Since most applications store data in your system's registry, it is likely that your registry has suffered fragmentation and accumulated invalid entries which can affect your PC's performance. It is recommended that you check your registry to identify slowdown issues