Windows stores time on the BIOS clock as Local Time, while other systems use UTC time. This means if you dual boot Windows with another system the clock will be messed up. Windows can be told to use UTC in the BIOS clock by a registry edit.
Advanced Configuration and Power Interface (ACPI) allows dynamic control of power to various computer components for use (as an example) in reducing power use when the computer is idle, or allow the computer to be automatically started just before the business day begins, or to turn on the computer and run maintenance tasks at night. There used to be a common Basic Input Output System (BIOS) setting where one could specify the day(s) of the week and time at which power should be turned on so the computer would boot, however this functionality has generally disappeared in main boards manufactured after the year 2000 and the “RTC Alarm” must be set programatically using an Operating System (OS). Readmore..