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ACPI_BIOS_ERROR during fresh Windows installation on new Ryzen 5 9600X system (ASUS BIOS 1402)

Arvin tabibi 0 Reputation points
2026-01-30T09:52:24.0433333+00:00

Hello,

I have a brand new PC build and I am trying to install Windows for the first time.
The system has never had any operating system installed before.

System Specifications:

CPU: AMD Ryzen 5 9600X

  • Motherboard: ASUS (TUF b850 m plus)

BIOS Version: 1402 (latest available)

  • RAM: 16gb DDR5 5200 viper venom (tested at default JEDEC speeds, no EXPO/XMP)

Storage: NVMe SSD

  • **GPU: not installed (**9600x igpu)

Boot Mode: UEFI only (CSM disabled)

Problem Description:

When booting from a Windows installation USB, the setup fails immediately and shows a blue screen with the error:

ACPI_BIOS_ERROR

This happens every time, before reaching the Windows installer interface.

What I Have Already Tried:

Reset BIOS to Optimized Defaults Disabled CSM (UEFI-only mode) Used GPT / UEFI Windows installation media Tried multiple USB flash drives Tried Windows 10 and Windows 11 (latest ISOs) Ensured no CPU or RAM overclocking Lowered RAM speed to default JEDEC values

Despite all of this, the ACPI_BIOS_ERROR persists.

Additional Notes:

The system powers on normally (fans, AIO, motherboard LEDs) BIOS detects CPU, RAM, and SSD correctly The issue only occurs during Windows installation This is a fresh build, not an upgrade or existing system

Question:

Is this a known ACPI / BIOS compatibility issue between recent ASUS BIOS versions (1402) and Ryzen 9000 series CPUs during Windows installation?

Is there any Windows-side workaround, or does this indicate a firmware-level issue that must be addressed by the motherboard manufacturer?

Windows for home | Windows 11 | Performance and system failures
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2 answers

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  1. Sin-D 10,015 Reputation points Microsoft External Staff Moderator
    2026-01-31T07:13:12.97+00:00

    Hi Arvin tabibi,

    Thanks for reaching out to Microsoft Q&A Forum. I understand you are encountering an ACPI_BIOS_ERROR immediately when booting the Windows installation media on a new system build.

    Please make sure you have already tried any automated suggestions provided by Q&A Assist. In addition, please try to follow these steps:

    1, Create a new Windows installation USB using the Microsoft Media Creation Tool on a different, known‑working PC, then boot the USB in UEFI mode by selecting the entry that explicitly shows UEFI in the boot menu. https://www.microsoft.com/software-download/windows11

    2, Enter BIOS Setup, then load Optimized Defaults and manually confirm Secure Boot is set to Windows UEFI Mode and OS Type is set to Windows UEFI, then save changes and restart.

    3, Temporarily disable all non‑essential onboard devices in BIOS, including Wi‑Fi, Bluetooth, RGB, and additional controllers, then retry the Windows installation.

    4, Update the motherboard BIOS again using ASUS EZ Flash with the same version 1402, even if it is already installed, to ensure the firmware is not corrupted during the previous flash.

    5, If available in BIOS, set ACPI Settings to default or Auto and disable any advanced power management or experimental CPU features, then retry the installation.

    6, If the issue persists, test the installation using a different NVMe slot or a different NVMe drive if available, then retry booting the Windows installation media.

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  2. AI answer

    2026-01-30T09:52:40.54+00:00

    The ACPI_BIOS_ERROR during Windows installation on your new Ryzen 5 9600X system could be related to compatibility issues between the BIOS and the hardware configuration. Given that you are using the latest ASUS BIOS version (1402) and have already tried several troubleshooting steps, it's possible that this is a known issue with the BIOS and the Ryzen 9000 series CPUs.

    Here are a few considerations:

    • Firmware Compatibility: Sometimes, newer CPUs may have compatibility issues with certain BIOS versions. It may be worth checking if there are any newer BIOS updates available or if ASUS has released any notes regarding compatibility with Ryzen 9000 series CPUs.
    • UEFI Settings: Ensure that all UEFI settings are correctly configured for your installation. Since you have disabled CSM and are using UEFI-only mode, double-check that the boot order is set correctly and that the installation media is recognized as UEFI.
    • Windows Installation Media: Although you mentioned using GPT/UEFI installation media, ensure that the USB drive is properly formatted and created using tools like the Windows Media Creation Tool to avoid any corruption issues.

    If the problem persists, it may indicate a firmware-level issue that needs to be addressed by the motherboard manufacturer. You might also want to reach out to ASUS support for any specific guidance related to the ACPI error with your motherboard and CPU combination.

    References:

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