The WCH CH382L is a dual-port parallel interface chip (often found on PCIe expansion cards) that provides LPT (Printer Port) functionality on modern motherboards lacking native parallel ports. To use this chip on Windows 10, the correct signed driver from WCH (Nanjing Qinheng Microelectronics) is required.
Note: Windows 10 does not include native drivers for the CH382L. Manual installation is necessary. wch ch382l driver windows 10
Windows 10 may turn off the PCIe port to save power, breaking serial connections. To disable: The WCH CH382L is a dual-port parallel interface
| Issue | Solution | |--------|----------| | “Driver not signed” | Disable driver signature enforcement (see step 3.1) | | COM port not working | Change COM port number in Device Manager → Port Settings → Advanced | | Device disappears after reboot | Disable Windows 10 fast startup (Power Options → Choose what power buttons do) | | Conflict with USB 3.0 | Try USB 2.0 port (CH382 is USB 2.0 compliant but some USB 3.0 hubs cause issues) | Note: Windows 10 does not include native drivers
For specialized uses (e.g., EPP/ECP modes for hardware programmers), some users replace the WCH driver with libusb-win32 via Zadig tool. This is not recommended for standard printer use.
| Error Code | Description | Solution |
|------------|-------------|----------|
| Code 10 | Device cannot start | Reinstall driver after disabling signature enforcement. Check IRQ conflicts. |
| Code 31 | Driver is not working | Use pnputil /delete-driver to remove corrupted entries, then reinstall. |
| Code 39 | Driver corrupted | Run sfc /scannow and reinstall from official package. |
| Code 52 | Unsigned driver | Follow Part 5 to disable signature enforcement. |
| LPT port not showing | PCIe card not detected | Reseat the card, update BIOS. Ensure PCIe slot is functional. |
| Blue screen (BSOD) on boot | Incompatible .SYS file | Boot into Safe Mode, uninstall driver, download newer version. |