Power Management

Advanced Power Management (APM) is the previous version power management solution that was introduced in Windows 95. ACPI supercedes APM. While Microsoft strongly recommends using systems with an ACPI-capable BIOS, Microsoft recognizes that many computers only support APM

Windows 2000 Professional has limited support for APM, and that support is intended only for older portable computers. It is not designed for use on desktop computers or other computers that do not use batteries for system power.

Microsoft places portable computers in one of three categories based on the support for APM offered by the systems. Windows 2000 Professional recognizes the following categories:

AutoEnable APM    During installation of the operating system, Windows 2000 Professional Setup automatically installs and enables APM on systems in this category, and the APM tab is present when you open Power Options in Control Panel.

Disable APM    Microsoft has determined through testing that APM does not work properly on systems in this category. During installation of the operating system, Windows 2000 Professional Setup does not install APM. The APM tab is not present in Power Options.

Neutral Systems    The APM functionality of systems in this category has not been determined. During installation of the operating system, Windows 2000 Professional Setup installs APM, but does not enable it. You can manually enable APM support on the APM tab of Power Options in Control Panel.

For more information about APM, see Mobile Computing in this book. For more information about APM and ACPI BIOS detection, see the Microsoft Knowledge Base link on the Web Resources page at https://windows.microsoft.com/windows2000/reskit/webresources . Search for the articles Windows 2000 and Advanced Power Management (APM) Support and How Windows 2000 Determines ACPI Compatibility.