To get your adapter working again, follow these steps to force Windows to use the older driver version: Prolific USB-to-Serial Comm Port (COM4) Driver for System
To use version 3.2.0.0 on modern systems, you must manually "backdate" the driver because Windows Update will automatically overwrite it with a newer, non-functional version. Obtain the Driver : Download the version 3.2.0.0 installer (often found as
: Run the 3.2.0.0 installer. If it asks to uninstall a newer driver first, allow it to do so.
: This version is highly recommended for older PL-2303HXA and PL-2303X chips that reached End-of-Life (EOL) and are no longer supported by modern Prolific drivers.
Windows may try to "helpfully" update this driver back to a newer, broken version later. If the error returns, you can use the "Roll Back Driver" button in the device properties or disable automatic driver updates for that specific hardware.