Whenever you connect the Apple device to the computer starts the backup procedure. It takes awhile and in the process of this operation is to copy any data, a user of a computer cannot.
Sign out of iTunes to disable backup. To exit, click on "File" - "Exit" or the key combination Win and Q keyboard.
Open the file that stores all program settings. It is located in the directory "start" - "Computer" - "Local disk C:" - Users - "your user Name" - AppData – Roaming – Apple Computer – iTunes. In this directory are XML documents that store part of the app settings.
Copy file iTunesPrefs.xml to any folder on your computer as a backup to in case of problems when editing a document you can always restore the program.
Open the document in the iTunes folder with any text editor except Notepad. You can use the Notepad++ which can be downloaded from the official website of the developer of the utility.
Go to the section User Preferences and paste the following code after the start of the section <dict>:

After inserting the code, save the changes. Use the tab "File" - "Save". Now you can launch iTunes. Procedure disable auto-sync completed.
If you use the operating system MacOS on your personal computer, disabling the startup can be performed via the terminal. Open the console using the corresponding menu item of the system and enter the query:

defaults write DeviceBackupsDisabled -bool true

After that press Enter. Connect the device to your computer and sync your computer with your phone. Disable automatic backup is completed.