How to fix avshws.sys driver with {The driver input point cannot be found} (errorcode=39)

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How to fix avshws.sys driver with {The driver input point cannot be found} (errorcode=39)

PENG TONG 50

I successfully compiled the project file(Windows-driver-samples-main\avstream\avshws) using VS2022 and generated the avshws.sys，avshws.inf，avshws.cat. Install the driver according to the "README.md" on Win10 22h2. It is not going well,

"Windows is unable to load the device driver for this hardware. The driver may be damaged or missing. (Code 39)

{The driver input point cannot be found}

%hs The input point cannot be found in the %hs device driver (%hs within the driver)."

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Answer 1

Tom Tran (WICLOUD CORPORATION) 4,765 Microsoft External Staff Moderator

Hi @PENG TONG ,

This error usually indicates a mismatch in the driver binary at load time rather than an installation issue.

There are reports with the avshws sample where incorrect project configuration can lead to this behavior, but the exact setting varies depending on the environment, so I don’t want to assume that’s the root cause here.

To narrow this down, could you confirm:

The WDK version used to build the driver
Your Windows version and build (winver)
The target architecture (x64, x86)
Whether you built Debug or Release
Whether Test Signing mode is enabled (bcdedit /enum | findstr testsigning)

Also, please check C:\Windows\INF\setupapi.dev.log and share any lines mentioning avshws, this will show the exact entry point Windows couldn't resolve, which is the most useful piece of information here.

PENG TONG 50 Reputation points

2026-03-25T08:49:36.5266667+00:00

setupapi.dev.log

Test mode is on.
Tom Tran (WICLOUD CORPORATION) 4,765 Reputation points Microsoft External Staff Moderator

2026-03-25T09:51:48.2433333+00:00
Thanks for sharing the log.

It seems the install completes successfully, but the failure happens when Windows attempts to start the driver:

CM_PROB_DRIVER_FAILED_LOAD (0x27) with status 0xc0000263

This status indicates the driver failed to load because a required entry point could not be found, which typically points to a binary compatibility issue rather than an installation or signing problem.

In many cases, this happens when the driver is built against APIs or configurations that are not available on the target OS.

To narrow this down, could you confirm:

The exact WDK version used to build the driver

Whether any project settings (e.g. target OS version or toolset) were modified from the sample defaults

Whether the issue reproduces with a clean rebuild (no changes to the sample)

If possible, also try building and testing on a newer Windows version to see if the behavior changes this can help confirm whether it’s a compatibility mismatch.
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Tom Tran (WICLOUD CORPORATION) 4,765 Reputation points Microsoft External Staff Moderator

2026-04-03T10:25:19.79+00:00
Hi @PENG TONG ,

Sorry for the late response on this.

Thanks for sharing your setup.

From the log, the driver installs correctly but fails to start with: 0xc0000263 (STATUS_DRIVER_ENTRYPOINT_NOT_FOUND), which means Windows cannot find a required entry point in the driver at load time.

Since your WDK/SDK and target OS all align, this is most likely coming from how the driver was built rather than the environment.

Could you try the following:

Rebuild the sample without any modifications (clean → rebuild → reinstall)

Confirm you are building for x64 Release

Check if the issue still reproduces with the unmodified sample

If it still fails after that, let me know.
Tom Tran (WICLOUD CORPORATION) 4,765 Reputation points Microsoft External Staff Moderator

2026-04-07T02:15:24.1233333+00:00

Hi @PENG TONG ,

I'm just checking in to see if you have any questions, please feel free to comment below. I'll be happy to assist!

Answer 2

The Code 39 error indicates that Windows cannot load the avshws.sys driver because the driver binary is failing to load. For this sample, the typical cause is incorrect or outdated project/build settings that produce a driver binary that does not match the target OS or its dependencies.

To fix the avshws.sys driver in this scenario:

Update the avshws sample project settings to the current WDK/Visual Studio toolset so that it matches the Windows 10 22H2 environment.
Rebuild the driver (avshws.sys, INF, CAT) with the corrected project configuration.
Reinstall the driver so that Device Manager picks up the newly built binary.

This aligns with the reported resolution where adjusting the project settings resolved the CM_PROB_DRIVER_FAILED_LOAD / Code 39 problem for avshws.

References:

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How to fix avshws.sys driver with {The driver input point cannot be found} (errorcode=39)

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