Windows key+R. Type in
explorer
and press Enter (or click OK).
Go to This PC and you should see the Note 4. (The beep is the data pins, not the charging pins, so the computer is seeing the phone, you just set the option to not pop anything up when you plug the phone in.) If you don't see the phone, right-click an empty space in the window in the drives or network area click , then click View, then click Expand all groups.
If you want the popup every time you plug the phone in, go to Control Panel/Autoplay, scroll down to the phone and set it to ask every time.