Windows XP [Electronic resources] : Visual Quickstart Guide, Second Edition نسخه متنی

Conserving Power

Environmental and money concerns make power management an issue for desktop as well as laptop users. Control Panel's Power Options utility lets you configure hardware features that reduce power consumption, affect how the power switch works, and extend the life of computer parts by turning them off or switching them to a low-power state. The tabs and controls displayed in the Power Options Properties dialog box depend on the type of computer that you're using (Figure 4.70 ).

Tips

To use your computer's power-management features, you may have to turn them on in your system BIOS. When you boot your PC you can configure the BIOS by pressing a key combination before Windows starts; read the documentation that came with your computer or motherboard for details, or watch the boot screen carefully for instructions on what key to press. Be quick to press it before Windows starts.

If your computer's components don't comply with the industrywide Advanced Configuration and Power Interface (ACPI) specification (also called OnNow), some power-management features may be unavailable or unpredictable. Older, non-ACPI-compliant computers have an APM tab (Advanced Power Managementan older standard) in the Power Options Properties dialog box.

Uninterruptible Power Supply

An Uninterruptible Power Supply (UPS) is a sealed backup batteryconnected between the computer and the electrical outletthat kicks in to keep your computer running if power fails. The UPS's capacity is expressed in minutes available to save your work and shut down normally during a power outageabout 5 minutes for a cheap UPS and up to about 30 minutes for better ones. UPSes also protect against power surges, spikes, and brown-outs (low voltage), which damage hardware more than blackouts. Don't forget to plug your monitor into the UPS. You also can plug in a power strip for extra sockets and keep your modem, printer, and electric stapler safe too.

A UPS doesn't really

have to interact with Windows, but Windows includes built-in support for monitoring that sounds power-failure alerts, displays remaining UPS-battery time, andif power becomes dangerously lowshuts down the computer automatically. A UPS that plugs into a USB port will install its driver and make the Power Options UPS tab vanish, replacing it with Alarms and Power Meter tabs.

To optimize your computer's power use, Windows uses a

power scheme a collection of settings that reduces the power consumption of certain system devices or of your entire system. You can use the power schemes provided with Windows or create your own, as you can a desktop theme.

To choose a power scheme:

1. Choose Start > Control Panel > Performance and Maintenance > Power Options > Power Schemes tab (Figure 4.71 ).

2. In the Power Schemes section, choose a scheme from the drop-down list.

3. To customize a power scheme, in the Settings section, change the default time settings.

4. To create a new power scheme, select the time settings that you want; click Save As; type a name; then click OK.

5. To delete a power scheme, select it in the Power Schemes list; then click Delete.

6. Click the Advanced tab (Figure 4.72 ).

7. To put a power-plug (or battery) icon in the notification area, check Always Show Icon on the Taskbar.

Click this icon to choose a power scheme, or double-click it to open the Power Options utility.

8. To password-protect your computer during standby or hibernation, check Prompt for Password.

9. Click OK (or Apply).

Table 1.1 in Chapter 1.

Older systems may not support standby, hibernation, or software shutdown (powering off without the switch).

Logging On and Logging Off" in Chapter 1, you can choose Start > Turn Off Computer to stand by or hibernate manually, but it's faster to use the computer's power or sleep button.

To use the computer's power button to stand by or hibernate:

1. Choose Start > Control Panel > Performance and Maintenance > Power Options > Hibernate tab (Figure 4.73 ).

2. Check Enable Hibernation.

3. Click the Advanced tab (refer to Figure 4.72).

4. In the Power Buttons section, select the action your computer takes when you press the Power or Sleep button.

5. If you're using a laptop computer, choose Stand By from the drop-down list below When I Close the Lid of My Portable Computer.

6. Click OK (or Apply).

For laptop computers, you can set alarms that sound or appear when the battery is almost out of power. Windows gives two distinct warnings: a

low-battery alarm and the more urgent

critical-battery alarm. When you hear either you should save your work immediately. The alarm options let you specify which alarms you want (low-battery, critical-battery, or both); how you want to be notified (text, sound, or both); and what the laptop should do in response to the alarm.

To set a warning alarm for a low- or critical-battery condition:

1. Choose Start > Control Panel > Performance and Maintenance > Power Options > Alarms tab (Figure 4.74 ).

2. In the Low Battery Alarm and Critical Battery Alarm sections, check either or both boxes to set the alarms.

3. Drag the slider to change the power-level threshold.

(Experience with the particular computer helps here.)

4. Click Alarm Action to specify what happens when an alarm goes off (Figure 4.75 ).

5. Click OK (or Apply).