Advanced Configuration and Power Interface

ACPI and Plug and Play work together to provide

• Automatic and dynamic recognition in installed hardware
• Support of docking and undocking
• Connecting PC Card devices
• Hardware resource allocation
• Device driver loading
• Power management and OnNow - ACPI is the foundation for the OnNow industry initiative that allows system manufacturers to deliver computers that start at the touch of a keyboard.

To find out if your computer supports ACPI, check the computer driver in Device Manager as shown in the following dialog.

If ACPI is not fully functional on a computer, check with the manufacturer for a BIOS upgrade.

ACPI is implemented at the lowest level in Windows in the HAL Hardware Abstraction Layer. HAL is implemented in HAL.DLL. There are different versions of HAL.DLL on the Windows CD-ROM. The appropriate version is installed when you run Setup. If you upgrade your computer BIOS to support ACPI, you must run Setup again to configure and install the correct version of HAL.DLL. Device Manager can be used to update from a single process to a multiprocessor HAL, but not to upgrade between standard and ACPI HAL.

Keyboard Exercise

Start Device Manager and check to see if your computer supports ACPI.