Question 1

Install fails or shows a warning in Device Manager?

Accepted Answer

Unplug the converter, uninstall any old USB-to-serial driver under Ports and USB controllers, reboot, then run the manufacturer installer as administrator before reconnecting.

Question 2

Device not detected or no COM port appears?

Accepted Answer

Try a different USB port/cable, check Device Manager for “USB Serial Converter” or an unknown device, and use Show hidden devices plus Scan for hardware changes. Install the driver before plugging in the adapter.

Question 3

Version conflicts or COM port changes?

Accepted Answer

Remove duplicate/generic converter drivers, use the manufacturer driver matching your Windows version, and assign a fixed COM port under Port Properties > Advanced if the number keeps changing.

USB Serial Converter Driver