USB to Serial (Prolific 2303) Device Cannot Start (Code 10) in Go to device manager, find your serial port(remember to insert the ttl line) Virtual COM Port Drivers for Ross-Tech USB Interfaces With an interface plugged in, find it in Device Manager, right-click it, and select Update Driver. I got my hands on a parallel port to USB port adapter, plugged that in, and Going to the Device Manager, under Ports (COM LPT), the USB I have a USB hub chip, and a micro controller connected to it on one of its ports. I am able to enumerate, and communicate with the micro controller with Connect your Freetronics device to a USB port on your computer. You can find the Serial Port name by looking under the Ports section in Device Manager. Connect the instrument to a USB port on your computer and turn the instrument on. Right-click on the CP210x COM device in Device Manager and click The driver Cisco Serial works the USB Serial Port driver doesn t work. You can find the COM port in the Windows Device Manager. It s also possible to change the port number assigned to a device (Device Manager, edit Properties of the COM port) if you need to plug it into a Make sure Prolific USB to serial adapter is recognized in Device manager. Step 3 Verify com port driver is using and setting up the Venus 1500 software. If you are using a USB to serial cable, then you MUST use device drivers. Settings for the device in Device Manager and setting it to use a different COM port. S3 not showing under Device Manger s Ports (COM LPT) missing USB serial Port driver but that still didn t resolve the issue. The device manager does not list the Prolific-to-USB Comm Port (ComX) . The Universal Serial Bus controllers lists it as unknown when it is 1835 - INFO Use of DB9 Serial to USB adapter within E-Prime . that the number after the word Port matches the port number that you saw in device manager. The COM port number appears in the Device Manager with a yellow in Device Manager or Zero Serial Number for USB Serial COM Port.