Recurring ACPI_BIOS_ERROR (0xA5) on HP ProBook 445 G10

[Andxxx]

Hello HP Community,

I have an HP ProBook 445 14-inch G10 Notebook PC running Windows 11 25H2 (64-bit).

I am experiencing a recurring startup issue approximately every 2–3 weeks. When I turn on the laptop, I receive the message:

"Your computer ran into a problem and needs to restart. We'll restart it for you."

The laptop does not restart automatically, so I have to hold down the power button to turn it off and then turn it on again. Windows eventually starts, but startup can be slow.

The stop code I identified during one occurrence was ACPI_BIOS_ERROR (0xA5).

My current BIOS version is HP V78 Ver. 01.14.01, dated July 6, 2026.

I ran sfc /scannow as an administrator, and Windows reported: "Windows Resource Protection did not find any integrity violations."

I also checked C:\Windows\Minidump, but the folder was empty.

The HP support website lists BIOS package 01.14.01 Rev.A, released July 27, 2026. The version number is the same as my currently installed BIOS, so I would like to confirm whether this package contains a newer revision and whether installing it could help resolve the recurring ACPI error.

What troubleshooting steps do you recommend? Could this issue be caused by the BIOS, ACPI, a driver, or a hardware problem?

Thank you.

[VikramTheGreat]

Hi @Andxxx,

Welcome to the HP Support Community.

Thank you for providing the stop code, BIOS version, and troubleshooting already completed.

The ACPI_BIOS_ERROR (0xA5) occurs during communication between Windows and the system BIOS or firmware. Since the error appears during startup and the Windows System File Checker found no integrity violations, please update the BIOS and the available HP chipset, graphics, and firmware drivers.

The BIOS page lists 01.14.01 Rev.A. Even though the numerical version matches the currently installed BIOS, you can download and run the listed package. The installer will verify whether the update applies to the notebook.

Update the BIOS

1. Connect the original HP AC adapter.
2. Disconnect unnecessary USB devices and docking stations.
3. Save your work and close all applications.
4. Ensure that you have the BitLocker recovery key, then suspend BitLocker protection.
5. Open the HP ProBook 445 14 inch G10 Notebook PC undefined page.
6. Select Windows 11, expand BIOS, and download the listed BIOS package.
7. Run the downloaded SoftPaq and select Update.
8. Do not turn off the notebook or disconnect the AC adapter during the update.
9. After Windows starts, resume BitLocker protection.

The model-specific page provides the available Windows 11 BIOS and drivers for this notebook.

After updating the BIOS, install the available AMD chipset, graphics, system firmware, and related driver updates from the same page.

BIOS USB option
If the BIOS installation fails, run the downloaded BIOS SoftPaq on another Windows computer with a blank USB flash drive connected. If the HP BIOS Update and Recovery window provides Create Recovery USB flash drive, select it and follow the prompts.

However, this ProBook generation uses HP Sure Start. Standard manual or USB BIOS recovery is not supported on HP Sure Start systems because BIOS recovery is managed automatically. Use the USB option only if the BIOS installer specifically offers it for this notebook.

Follow the complete BIOS instructions here: HP Business Notebook PCs - Updating the BIOS (Basic Input Output System) | HP® Support
 

If the error continues, restart the notebook, press Esc, then F2, and run the System Fast Test and System Extensive Test. If a test fails, note the 24-digit Failure ID displayed.

Take care and have an amazing day!