[Com0com-user] com0com Installation Issue (Code 52) with Secure Boot Enabled on Windows 10

[Foad S. F. <f.s...@gm...>]

Hello com0com Developers and Users,

Following questions here <https://stackoverflow.com/q/79545926/4999991>,
here <https://sourceforge.net/p/com0com/code/>, and here
<https://superuser.com/q/1889354/588662>, I'm seeking assistance with
installing the com0com virtual serial port driver on my Windows 10 system.
I am encountering the "Code 52" error (Windows cannot verify the digital
signature) for the com0com devices, preventing the driver from loading.

My Environment:

   - Operating System: Windows 10 (Latest Updates)
   - Secure Boot: Enabled (Policy prevents disabling it)
   - BitLocker: Active


Background:

I initially installed com0com via a Chocolatey package which, I later
discovered, used an older, unsigned driver version. This caused persistent
issues. I have since corrected the Chocolatey package
<https://github.com/Foadsf/com0com-chocolatey> to use the official
*com0com-3.0.0.0-i386-and-x64-signed.zip* package.

However, even after attempting a thorough uninstallation, I cannot get the
signed driver to install correctly. On a clean virtual machine, installing
the signed package correctly prompts with the "Windows Security - Would you
like to install this device software?" dialog showing "Publisher:
CyberCircuits".

[image: vmconnect_C5FFYI4RGe.png]

On my physical machine, this prompt does not appear, and the installation
ultimately fails to load the driver, often resulting in the service failing
to start with error %%577 or devices showing Code 52 in Device Manager.

Troubleshooting Performed:

Attempted uninstall using setupc.exe uninstall from the signed package
directory (run as Administrator). The command output indicated successful
removal of devices, the service, registry keys, driver files (oemXX.inf
packages), and the custom class GUID.

Verified service removal with sc.exe delete com0com (reports service
doesn't exist).

Verified device instance removal using pnputil /enum-devices targeting
com0com hardware IDs and class GUIDs (reports no devices found).

Attempted to enable Test Signing mode using bcdedit /set testsigning on,
but this fails with the error: "The value is protected by Secure Boot
policy and cannot be modified or deleted." This confirms Secure Boot is
preventing the standard workaround for test-signed drivers.

Manually deleted associated registry keys and driver files (though setupc
uninstall seems to handle this now).

Rebooted the system multiple times between uninstallation and
reinstallation attempts.

Current Problem:

Despite the seemingly successful cleanup using setupc uninstall, when I run
the signed setup.exe (interactively, as Administrator), it proceeds without
showing the Windows Security trust prompt for the CyberCircuits publisher.
The installation finishes, but the devices remain unusable with the Code 52
error.

The Core Challenge:

I cannot disable Secure Boot due to system policies. I need com0com to
function using the provided signed driver under these constraints.

Questions:

Is there a more definitive method (perhaps using pnputil or registry edits
beyond what setupc does) to absolutely guarantee that all remnants of the
previous unsigned driver installation are purged, ensuring Windows only
considers the new signed package during installation?

Is the signed com0com-3.0.0.0 driver known to install and function
correctly on a Windows 10 system with Secure Boot enabled without requiring
Test Signing mode? (I assume the signature should allow this, hence the
expected trust prompt).

Could there be a conflict with the certificate store or a specific Windows
update that might interfere with recognizing the CyberCircuits signature,
even if Secure Boot itself isn't directly blocking that specific signature
(but rather blocking the attempt to enable Test Signing)?

Are there any known workarounds or alternative installation methods for
this specific scenario (signed driver, Secure Boot enabled and locked)?

Any insights or suggestions would be greatly appreciated. I'm happy to
provide further logs or details if needed.

Thank you for your time and expertise.

Best regards,
F.