Conserving laptop battery power, or simply managing the energy consumption of any PC can easily be accomplished by making adjustments in Windows Power Options.
There are a couple methods for accessing Power Options. One that will work in XP, Vista, or Windows 7 is through the Run command. The easiest way to bring up Run, is to use the keyboard shortcut (Win+R). In the Run dialog box, type (or copy and paste) powercfg.cpl
Or, in Vista and Windows 7, Run can be skipped altogether. Just type power options into Start search and hit Enter or click the Power Options link.
In Vista and Windows 7, the power plan choices are; Balanced, Power saver, and High performance. Power saver offers the most conservative use of energy; Balanced combines the Power saver plan and High performance. High performance is the gas guzzler of the three. The images shown here are from Vista, but are very similar to those found in Windows 7. Other settings options are available at the left. One of these, Choose what closing the lid does, is discussed below.
Clicking the Change plan settings link opens the Edit Plan Settings dialog box for the selected plan. There, settings can be tweaked to provide the desired mix of effectiveness and efficiency.
Any changes made, can be undone by clicking the Restore default settings for this plan link.
For more control, click the Change advanced power settings link. This will bring up Advanced settings  in the Power Options dialog box. This however, is designed for somewhat more advanced users.
Scroll down to make selections. Since conserving battery power is the focus of this section, Battery options are displayed above.
If you’d like to learn more about controlling your computer’s energy consumption, see the articles below.
However, Power Options doesn’t limit the user to power usage choices. It seems that every time I open it, another option is revealed. Unfortunately, this is more an indication of increasingly poor memory, than of new stuff appearing. On the bright side, I get to meet new people every day and can hide my own Easter eggs.
In Power Options, you can also control what happens when the lid on a laptop is closed. Just click the Choose what closing the lid does link.
Settings can be individually adjusted for when the laptop is running on battery, or for when it’s plugged in. The choices are Do nothing, Sleep, Hibernate, or Shut down. For details on each of these, see the tip, Change What Your Power Button Does .
Clicking the Change settings that are currently unavailable link offers the opportunity to change what happens when the computer wakes up.
This will probably bring up a UAC (User Account Control) warning. Just click Continue.
You can then choose whether or not to require a password on wakeup.
Take a look at Power Options. You won’t regret it (and I won’t remember it).