Prolific USB-Serial (9/4/2015) from Win Update, error 52 (signature)  

I have researched the Prolific USB-to-Serial driver issues. There's loads of information and mis-information regarding the Prolific chips, the counterfeit chips, and various driver versions. I've installed several different versions including 3.2.0.0 (7/31/2007), 3.3.2.105 (10/27/2008), 3.3.11.152 (3/12/2010). They all BSOD on my system.

The latest version from Windows Update is 3.6.81.357 (9/4/2015) and it works properly! Unfortunately it requires entering Advanced Boot Options at startup to disable driver signature checking. Otherwise it reports Code 52 (Windows cannot verify the digital signature for the drivers required for this device. A recent hardware or software change might have installed a file that is signed incorrectly or damaged, or that might be malicious software from an unknown source.) The driver lists two files which are both signed:
ser2pl64.sys (Microsoft Windows Hardware Compatibility)
serenum.sys (Microsoft Windows)

I have uninstalled the driver and re-installed the update from Windows Update with the same problem.

Is there a good solution or even a workaround?

This workaround is NOT working.

Code:

bcdedit.exe -set loadoptions DDISABLE_INTEGRITY_CHECKS
bcdedit.exe -set TESTSIGNING ON

fireberd said:

I have a Prolific USB/RS232C adapter and I don't have your problem.

Appreciate your post. I am also using an RTL2832U dongle, with WinUSB 6.1.7600.16385 drivers. I suspect the problem may be the combination of the two.

Well it's working, but F8 & Advanced Boot Options at every single start-up is rather annoying...

The workaround is to "sign" the drivers with the Driver Signature Enforcement Overrider, and to turn on (and leave on) Test Mode -- which can be done in the application or with

Code:

bcdedit.exe -set TESTSIGNING ON