After upgrading to Windows 10 from 8.1 on my Surface Pro 3 the Prolific RS232-USB driver is not functional as it was under Windows 8.1. The device manager reports for this device: 'This device is not working properly because Windows cannot load the drivers required for this device. (Code 31) Object Name already exists.' I followed all on-line advice for Code 31 and to no avail deleted the current driver and re-install, re-boot, and search for new hardware it does not fix the problem.
I find hints of the driver in the Registry but removing mention of the Prolific device may be problematic since it seems there are other devices I use regularly where removing the entry in the Registry may cause other issues. Matshita Bd Mlt Uj240es Driver Windows 10 here. As a further comment that is food for thought by Microsoft is that I find the lack of registry repair tool as available in Windows 7 is not a good move by the Technical Staff of Microsoft.