Disabling ACPI Support in BIOS Results in Error Message

If the Advanced Configuration and Power Interface (ACPI) option is enabled in your computer's BIOS when you initially install Windows 2000 and you later disable the ACPI option in your computer's BIOS, you receive the following error message on a blue screen when you start Windows 2000:

This behavior occurs because Windows 2000 uses a separate Hardware Abstraction Layer (HAL) for ACPI support.

If you want to disable ACPI support after Windows 2000 is installed, you must reinstall Windows 2000 with APCI disabled in the computer's BIOS. Because numerous changes are made to the registry and system files, an upgrade installation does not work.

This behavior is by design.