All modern computers are based on ACPI standard. This standard is used to configure and adjust an operation of the hardware – to assign interruptions and resources to the devices on PCI and AGP buses, to receive information about devices and for operation of additional “power-saving” buttons and sensors and other.
For example, a motherboard is able to support APCI standard while BIOS is incompatible with it. This situation is very real because motherboards are long-term manufactured using this standard but BIOS had recently used it. And only reflashing may help in this situation.
To switch ACPI standard on, use the parameter “ACPI Function” (IPCA Function) which is located in a section “Power Management Setup” (Power or Power Management Futures). This parameter may have two values: Enabled and Disabled. If this standard is enabled, the control over the expanded power control can be given to operating system. To do this, you may use the parameter “PM Control by APM” (Power Management/APM). This parameter may also have two values: Yes and No. If this parameter is enabled, some settings for other parameters (for example, Suspend Mode, HDD Power Down or similar to them) will be ignored in BIOS because, in this case, the control over the power was given to operating system. This parameter should be switched on only for Windows98 and the higher version.