After reboot, open Device Manager again. Your U232-P9 should now appear under "Ports (COM & LPT)" as "Prolific USB-to-Serial Comm Port (COMx)" without any yellow triangle. Double-check its properties; the Driver version should be 3.3.2.102 .
| Error | Likely Cause | Fix | |-------|--------------|-----| | Code 52 (driver signature) | Windows 10 default driver signing | Use Method 1 (disable signing + legacy driver) | | Code 10 (device won’t start) | Counterfeit Prolific chip with new driver | Uninstall v3.6+ driver, install v3.3.2.102 | | No COM port appears | Missing driver entirely | Install either Prolific legacy or CH340 driver | | Adapter works but disconnects | Power management | Device Manager → USB Root Hub → Properties → Power Management → Uncheck "Allow computer to turn off" | | Baud rate errors | Wrong chip driver | Confirm hardware ID, try alternative driver (CH340 or CP210x) |
Once installed, your software (like PuTTY, Arduino IDE, or industrial tooling apps) must match the driver configuration. u232 p9 driver windows 10
You need to download the specifically designed for Windows 10 compatibility.
This almost always means you are using a driver version that is too new for the physical chip inside the cable. Revert to an older version. After reboot, open Device Manager again
Setting up an older U232-P9 USB-to-Serial adapter on Windows 10 can be tricky due to chipset compatibility. These devices often use chips from or Prolific that are now considered "legacy" or "End-of-Life" (EOL) by their manufacturers. Understanding the U232-P9
If you need to check your current driver version, it is available in the Device Manager. If you're interested, I can also: Show you where to download the specific . | Error | Likely Cause | Fix |
Many counterfeit PL-2303 chips exist. Since Windows 8/10, Prolific has deliberately broken drivers for counterfeit chips. If your adapter is fake, the driver will install but show Error 10 (This device cannot start) or Code 28 .
: Ensure you download the version specifically for the U232-P9 chipset . 2. Installation Steps for Windows 10