The Power Options applet lets you manage the power consumption of your computer. Power savings is important when you're operating a laptop on battery power, but it's also important if you'd like to save money (and the environment) by cutting down on the amount of electricity your desktop PC uses.
As shown in Figure 8-18, the settings available in this control panel vary depending on the computer.
Figure 8-18. The Power Options options for a desktop PC (left) and laptop. Some of the tabs and options shown here don't appear until you click the APM tab and turn on "Enable Advanced Power Management support" (which isn't available on some older machines).
The Power Schemes tab lets you select, change, or create power schemes. A power scheme defines which components of your PC, such as your keyboard, mouse, or processor, shut down (to save power) after a certain amount of time since you last used them. Power schemes can save power using several different tricks:
Turn off monitor. Your monitor goes dark, and the power light on it changes from green to yellow.
Turn off hard disks. The hard drives stop spinning.
System standby. The computer goes into standby mode, which is something like being asleep. All of its components go into reduced-power mode. (Wake it up by pressing a key or clicking the mouse.)
System hibernates. Your computer hibernates (see "Hibernate Tab").
Note
The standby and hibernate options are primarily useful on laptops, and they appear only if you've turned on "Enable Advanced Power Management support," if available, on the APM tab described below. In addition, you'll be offered these controls only if your user account has been given administrative privileges, as described in Section 17.3.
You're welcome to change the settings for any of these schemes. (If you have a laptop that offers Advanced Power Management, as described below, you can create separate settings for "Plugged in" and "Running on batteries" conditions.)
Once you've done so, you can click Save As to preserve your new settings under their own new scheme name. Finally, click OK to close the Power Options Properties dialog box and put the selected power scheme into effect.
Notebook computers offer special options that help them conserve battery power. (You'll see these tabs only if you've turned on "Enable Advanced Power Management support," if available, on the APM tab.)
When your battery starts running out of juice, your laptop shows a warning message. When it's only got a few seconds of power left, you get a second, more urgently worded message. Both messages are designed to clue you in that now is a good time to save whatever document you've been working on; the laptop is about to go to sleep until you've plugged the power cord into the wall.
The controls on this tab let you specify when (or whether) these messages appear, what kind of notification you want (a message, a sound, or both), and what the laptop does as a result (such as going into standby mode).
This tab is your laptop battery's fuel gauge. If your computer has two batteries, turn on "Show details for each battery"; you'll see an icon for each battery, which slowly "empties" as your power runs down.
The Advanced tab, despite its impressive name, usually contains just two options. The first checkbox puts a power icon on the Taskbar tray. You can click this icon to produce a menu listing your power schemes.
If you select "Prompt for password," you're asked to enter a password. Thereafter, the PC won't wake up from standby mode until you've entered the password.
On some computers, an additional option called Power Buttons appears. It lets you choose how your computer will behave when you press the Off button. It can actually turn off—the default—or you can choose to go to Standby.
Hibernate is designed to shorten the long delays involved in shutting down and starting up again later. If you turn on "Enable Hibernate support," you'll see a new option (Hibernate) in the Shut Down Windows dialog box (Section 2.3). When you choose Hibernate as a shut down option, the system saves all your active work onto the hard drive, including open windows and documents—and only then shuts down. When you return to the computer and turn it on, the PC boots up as usual; if you've enabled "Prompt for password" on the Advanced tab, you'll be prompted for a password. After you provide it, the desktop opens instantly, with all programs running and documents open, exactly as you left it.
APM stands for Advanced Power Management, which refers to special power-saving circuitry available in many modern PCs. This tab (if your PC has it) contains nothing but an on/off switch, "Enable Advanced Power Management support." When you turn it on, you add a few useful power-management features to your PC.
For example, turning on APM adds a new option, Stand by, to the Shut Down dialog box. (Standby mode is a low-power condition that's a lot like Off, except that the computer continues to sip a small amount of power, and "wakes up" almost instantly when you press a key or click the mouse.) Turning on APM also gives you many more options on the Power Schemes tab described above, as shown at right in Figure 8-18.
Note
If your computer is compatible with a technology standard called ACPI (Advanced Configuration and Power Interface), you won't see an APM tab. That's because ACPI automatically enables the APM Features, so there's no need for an APM on/off switch. (You don't need to worry about knowing which your computer is; Windows 2000 Pro detects the power capabilities automatically).
A UPS (Uninterruptible Power Supply) is a device that shields your PC from power outages and fluctuations. You use this tab only if you actually have a UPS connected to your PC that Windows 2000 "sees"; you configure the UPS using the controls here. For example, you can configure your computer to display notifications at specified intervals when a power failure occurs, and to shut down after using battery power for a certain period of time. This feature lets the system shut down in a controlled manner, even when you're not around to help it.
Tip
For details on UPS devices, an excellent source of information is the UPS FAQ ( http://www.uga.edu/~ucns/lans/docs/ups.html ). The commercial site http://eHow.com ( http://www.ehow.com/home/ ) has simple instructions on choosing and setting up a UPS.