The U232-P9 USB-to-Serial adapter typically uses a chipset from Magic Control Technology (MCT) or Prolific. Finding a working driver for Windows 10 can be tricky because many of these devices use older chips that are officially "End of Life." How to Install the Driver on Windows 10
Alternative if above fails (for older chips):
For non-HXD chips (e.g., PL2303RA, HXA, EA), Prolific no longer supports Windows 10. You must use a Windows 7/8 driver with driver signature enforcement disabled (not recommended for security). u232 p9 driver windows 10