The user of a notebook computer can specify a lower-level of power consumption when the battery starts running low so that essential applications can still be used while other, less important applications are allowed to become inactive. The operating system can lower the clock speed during times when applications don't require the full processor clock speed. The operating system can reduce motherboard and peripheral device power needs by not activating devices until they are needed. The computer can enter a stand-by mode when no one is using it, but with modem power left on to receive incoming faxes.
Devices can be plug and play .
One of several power schemes can be chosen. Within a power scheme, the user can control the power to individual devices. In order for ACPI to work on your computer, your BIOS must include the ACPI software and the operating system must be ACPI-compatible. ACPI is designed to work with Windows 98 and with Windows 2000. ACPI is in part a response to global concerns about energy conservation and environmental control.