If you have iTunes installed chances are there is a startup process iTunesHelper enabled on your PC. According to Windows Task manager’s startup impact, it ranks iTunesHelper as High impact. Not sure what’s the algorithm for Microsoft on deciding the rankings on the starter programs, pretty sure it has nothing to do with the rivalry between Apple vs Microsoft. That aside, the real use of iTunesHelper is making iTunes launch faster if you connect your iPhone, iPod or iPad to the computer.
The era of syncing your iOS device to your PC has passed, most of us no longer sync any content between your phone and the computer over the wires, instead, all the data on your phone are synced with the cloud. It’s unnecessary to have iTunes launch every time when an iOS is plugged in for charging.
Go to Task Manager > Startup tab. Find iTunesHelper, right click and disable. It will help your PC to have a quick startup time, also eliminate iTunes to pop up everytime you connect your iOS devices completely. Yes, there is a setting within iTunes to specifically allow this configuration, but it will not prevent iTunesHelper to stop running on startup.