I'm using windows 10. Connected my phone (Samsung Note 3) to my PC but it only charges. I've done USB Debugging and even installed the driver on my PC. I doubt windows 10 doesn't recognized my phone because I connected to my windows 7 PC but the same thing happened.
Not all the USB cables offer data transfer. There are same-looking power-only cables, which obviously allow only charging, and don't have data wires at all.
Try with a different USB cable as a start.