Question 1

Device not detected or no COM port?

Accepted Answer

Use a data-capable USB cable, try another USB port, and check Device Manager for “USB-SERIAL CH340.” If missing, rescan hardware; if shown with an error, uninstall the device and reinstall the manufacturer’s CH340 driver.

Question 2

Install fails or driver will not load?

Accepted Answer

Run the CH340 installer as administrator, close antivirus temporarily, remove older CH341SER/CH340 packages, reboot, then reinstall. On 64-bit Windows, use the signed vendor driver.

Question 3

Version conflicts or wrong COM port?

Accepted Answer

Uninstall the existing CH340 device and delete its driver package in Device Manager, reboot, and install only the latest manufacturer driver. Then assign/confirm the correct COM port in your terminal software.

USB SERIAL CH340 Driver