A lot of folks have trouble with usb to rs232 adapters based on the prolific chip (or perhaps clone). Win 8.1 & windows 10 often give an error 10.
This link has a good explanation & fix (if you are brave enough to run it)...worked for me on win10
The Prolific 64-bit drivers that Microsoft supplies via Windows Update, Versions 220.127.116.115, 18.104.22.168, 22.214.171.124, and 126.96.36.1993 will not work with most adapters and issues the generic "Code 10" error. Or, you may get no error at all, but your device will not work. If your adapter was working prior to going to Windows Update, you can "roll back" to the previous installed driver and all will be well once again. However, if you didn't have a previous driver installed that worked, you'll have to go through the process of removing any PL-2303 driver installation programs, the actual driver files, and the information (.INF) file BEFORE you are able to successfully install the correct driver. What aggravates the issue is that there are many "Prolific Driver Removal Tools" that do not work properly as well! And Windows 8, 8.1, and Window 10 are set by default to automatically update your drivers without your permission or even notifying you of the update. So, no matter how many times you remove the driver files and reboot, the next time you insert the USB-To-Serial adapter, Windows installs the newest non-working version again. Yes, it's frustrating as hell.
The only 64-bit driver I have ever found that works with all the "Prolific" adapters is Version 188.8.131.52. The below installer program will remove all of the incompatible drivers, make a change so that Windows can never update the driver without your okay, and install the Version 184.108.40.206 compatible drivers.