What version of Windows are you using? If you're explaining a situation similar to that of the iPod, where instead of it asking you what you want to do every time you want to charge it, it instead just charges it. In Windows 7, the easiest way I know to do that would be to connect the device, wait for windows to prompt you, then select when these messages appear. You can select the particular device from the list and set the default to "Take no action."