Power settings for XP you can find in the Start Menu--> Settings--> open Control Panel--> open Power Options - now you have list of options:
Under the Power Schemes tab, you can select, create, modify, or delete power schemes. The following default schemes are available:
Minimal Power Management
Create multiple power schemes for different situations
Users can set when to turn off the monitor, hard disks, or standby/hibernate the system. These options are pre-defined, however; the user cannot set custom amounts of time for these events.
If you have a laptop, you can set separate times for battery and AC power for turning off the monitor, hard disks, system standby, and hibernation.
The Advanced tab gives the user options on whether to show the power icon in the taskbar (useful to show battery life), prompt for a password when the computer resumes from standby (although it only does so if fast user switching is disabled - otherwise, it displays the Welcome screen), and what to do when power buttons on the computer or keyboard are pressed (Shutdown, Standby, Restart, Hibernate, Do Nothing).
Configure advanced power options for your XP machine
The Hibernate tab allows the user to enable XP’s zero-power mode, called hibernation. Hibernating will save the state of everything currently open, and then shut down the computer. When returning from hibernation, XP will return to the state it was in previously, with all open windows and programs available as they were. Hibernate functions essentially the same way as sleep or standby; the difference is that it fully shuts the computer down instead of just putting it into a low-power state. Since the computer is literally turned off in this state, you can unplug it, move it to another location, and turn it back on without having to boot up again.
The UPS (Uninterruptible Power Supply) tab allows you to monitor your UPS status and configure its settings. XP can be set up to communicate and execute commands with the UPS.
Click Configure (if you have a serial connection to the UPS) to set up these options. You can configure XP to notify the user, execute an application, or shut down the computer when the UPS switches to battery power or the internal battery is getting low. You can even set up a convenient optional delay, so if the UPS kicks in for only a few seconds and then returns to AC power, your configured actions will not run.