BIOS Updates Fail with "Package 'Dell [MODEL] System BIOS' is not signed." in Dell Command Update

Summary: This article provides information about Dell Command | Update (DCU) failing with "EXE not signed" error when attempting to update the BIOS.

This article applies to This article does not apply to This article is not tied to any specific product. Not all product versions are identified in this article.
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Symptoms

Affected Products:

  • Dell Command | Update

Cause

Dell Client Management Service uses wintrust.dll (a system process that contains API functions to verify trust files), signatures, or certificates. As per the API output, Dell Client Management Service is not receiving 0 value when the WinVerifyTrust API from wintrust.dll is called on the affected computer.

Therefore, the signatures are not fetched from the Dell Update Packages.

Resolution

The engineering department has released a BIOS update to resolve this issue. The updated BIOS is posted to the computer's support page once it is made available.

Note:
  • There are various OptiPlex, Latitude, and Precision Workstations affected by this issue.
  • All BIOS updates posted by the end of January 2025 or later has an update to the certificate packaging, which resolves the issue.
  • Not all computers will receive a BIOS update by the end of January 2025, but all updates after this should contain the new certificate packaging.

Affected Products

Dell Command | Update
Article Properties
Article Number: 000239816
Article Type: Solution
Last Modified: 15 Jun 2026
Version:  11
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