It works with Arduino UNO but not with LEONARDO. Sometimes it says port occupied by other programme and sometimes just refer to Arduino trobleshooting. The usb driver is 54TI. I have checked the pc port admin ok. It works perfect on stationary pc with Windows 10. I do need it to work on the portable pc with Win 7 Starter, because the Arduino Leonardo is physical remotely installed. After spending many hours on this problen - can anyone help?????