In windows 7,you can change your power plan options to reduce the amount of power your computer uses, maximize performance, or balance to make your laptop battery last longer.
1.Go to Control Panel (Small Icons View) and click Power Options
2.In the left pane of Power Options window,you can Create a power plan or choose when to turn off the display or choose what the power button does or if disable password when wakeup
3.In the right pane of Power Options window,you can select a power plan and change Power plan settings
4. After Click Change plan settings ,you can click Change Advanced Power settings to customize other advanced Power options
5.In the Advanced Power Options window,you can customize more power options such as enable or disable hibernate ,change the power options of disk / cpu / monitor and so on