If it is charging, then your computer should recognize that something is plugged up to it through the USB cable. Try plugging the USB cable into one that you know is working. I think you have to make sure it is USB 2.0 so that it can transfer that much information and so that it can charge the phone. The computer should at least recognize that it has an external hard drive or something, some icon should pop up on the Windows I would assume.
I have the old Iphone, so I wasn't able to do anything until it was plugged up to my computer anyway.