Quick Summary
The error code 0x000000A5, also known as ACPI_BIOS_ERROR, indicates that the Advanced Configuration and Power Interface (ACPI) BIOS in your computer might not be fully compliant with the ACPI specification. It can also result from hardware incompatibility or corruption during the ACPI initialization process.
Common Causes
- Incompatible or Corrupted ACPI BIOS: The ACPI BIOS on your motherboard is outdated, corrupted, or not fully compliant with the ACPI specification. This can prevent Windows from properly configuring power management and hardware resources.
- Hardware Incompatibility: A newly installed hardware component is incompatible with the ACPI implementation of your motherboard. This is especially common with older hardware or components not fully tested with the specific motherboard model.
- Driver Issues: Faulty or outdated drivers, especially those related to chipset, motherboard, or power management can cause ACPI-related errors. Corrupted or incorrectly configured drivers can interfere with the ACPI initialization process.
- Operating System Errors: Corruption within the operating system, particularly in system files related to ACPI or power management, can also result in this error. This can be caused by disk errors, malware, or incomplete Windows updates.
Step-by-Step Fixes
Method 1: Update or Flash your BIOS
Warning: Flashing the BIOS is a potentially risky operation. Incorrectly flashing the BIOS can brick your motherboard. Only proceed if you are comfortable with this process and have consulted your motherboard's manual.
Step 1: Visit your motherboard manufacturer's website and download the latest BIOS version for your specific motherboard model.
Step 2: Follow the manufacturer's instructions to properly flash your BIOS. This usually involves using a USB drive and a BIOS flashing utility.
Step 3: After the BIOS has been successfully flashed, restart your computer, and check if the error persists.
Method 2: Update Device Drivers
Step 1: Open Device Manager by searching for 'Device Manager' in the Windows search bar.
Step 2: Look for devices with yellow exclamation marks, indicating driver issues. Pay close attention to chipset, motherboard, and power management controllers.
Step 3: Right-click on each problematic device and select 'Update driver'.
Step 4: Choose 'Search automatically for updated drivers'.
Step 5: If Windows doesn't find a driver, visit the manufacturer's website (e.g., Intel, AMD) and download the latest drivers for your hardware.
Step 6: After updating the drivers, restart your computer.
Method 3: Disable ACPI in BIOS (Temporary Solution)
Note: This is a temporary workaround and will disable some power management features.
Step 1: Restart your computer and enter the BIOS setup. The key to enter BIOS varies depending on the manufacturer (usually Del, F2, F12, or Esc).
Step 2: Look for ACPI or Power Management settings. The location varies but is often under 'Advanced' or 'Power'.
Step 3: Disable ACPI or set the ACPI mode to 'Legacy' or 'Disabled'.
Step 4: Save the changes and exit the BIOS setup.
Step 5: Restart your computer. Check if the error is resolved. If this resolves the issue, it strongly suggests the ACPI BIOS is the problem, and you should continue to investigate updating or replacing your BIOS.
Method 4: Run System File Checker (SFC)
Step 1: Open Command Prompt as administrator. Search for 'cmd' in the Windows search bar, right-click on 'Command Prompt', and select 'Run as administrator'.
Step 2: Type sfc /scannow and press Enter.
Step 3: Wait for the scan to complete. This process may take some time.
Step 4: If SFC finds and repairs corrupt files, restart your computer.
Method 5: Check Hardware Compatibility
Step 1: If you recently installed new hardware, remove it to test for compatibility issues.
Step 2: Consult the motherboard's documentation for compatible hardware lists.
Step 3: Check that the new hardware isn't drawing too much power from the power supply.