[Osiris]

Source PC Power Management Software PowerSlave

There is no built in way of working effectively with different power profiles in the Windows operating system. Microsoft is only offering one power profile in Windows XP and two (battery and plugged in) in Windows Vista. There are no PC power management options that allow a user to define power profiles based on time and day. This would make sense as the requirements could be different throughout the week.
A user who needs to access the computer system quickly at work does not necessarily wants to use a energy saving power profile that shuts down the computer monitor, hard drives or even hibernates. The situation might be different at home for the same user where time is normally not a pressing matter.