I'm afraid that there is no solution... There is lot's of people reporting problems with W10 and Prolific devices (based on popular PL2303 adapter). Myself, I've the same problems with scrolling LED Badges, and USB to COM dongles. All this devices use a PL2303 to provide a connection to an USB port, but inside, they are RS232-like interface build (and appear as a COM port in your operating system). When you plug the device into USB, it is well recognized by W10 and it try to load the Prolific driver. This work fine, but looking at the configuration panel, you will then notice that there is an error code 10 and the driver is not working properly.
Of course, you can try to manually update the driver at Prolific site:
But, look carefully on this page and you will read an important notice in RED :
Windows 8/8.1/10 are NOT supported in PL-2303HXA and PL-2303XEOL (End Of Life) chip versions.
Prolific USB Drivers Download by Prolific Technology Inc After you upgrade your computer to Windows 10, if your Prolific USB Drivers are not working, you can fix the problem by updating the drivers. It is possible that your USB driver is not compatible with the newer version of Windows.
Prolific Driver 3.3.3.114 Download
Prolific also prohibits the distribution of any PL-2303 drivers (including download links) without written permission from Prolific. Prolific advices end-users to only purchase vendor branded cable products with company name contact information for service and support. Prolific does not sell cables with Prolific brand and packaging.
Windows: No driver installation is necessary for Windows 10, 8.1, 8, or 7 computers that are connected to the internet. The operating system will download the correct drivers automatically when the Plugable USB to RS-232 DB9 Serial Adapter is plugged in.
This is clear: if your device is using an old chip version of PL2303, the drivers not works with W10 (and W8).
Prolific 232 Driver Download
As many people, you probably upgrade directly from W7 to W10, and sure, don't know that this problem was already present with W8. It's a shame from Prolific to not support this devices, because they are still used (my LED badges are less than a year old, and use EOL PL-2303 HX). Prolific's guys are fun when they said : 'Prolific recommends to use PL-2303HXD (HX Rev D) or PL2303TA chip.' . Hey, but I can't do that myself !!!
I don't want to send my devices to trash because they are too old (less than a year !) to be supported by W10. May be, a solution will be to use the old W7 drivers version into W10. Not tested... I will try...