ituneshelper.exe is a process belonging to Itunes MP3 streaming tool by Apple, which allows you to play MP3's.
This process speeds up iTunes when it starts, and the program also monitors for connected iPod devices.
This is a non-essential process. Disabling or enabling it is down to user preference.
Non-system processes like ituneshelper.exe originate from software you installed on your system. Since most applications store data in your system's registry, it is likely that over time your registry suffers fragmentation and accumulates invalid entries which can affect your PC's performance. It is recommended that you check your registry to identify slowdown issues