To have your monitor automatically turn off
1) Go to control panel to view Display properties.
2) To switch your monitor to standby after a specified period of time, make sure the Low-Power Standby box is checked. To turn off your monitor after a specified period of time, make sure the . Shut Off Monitor box is checked.
3) In the corresponding Minutes box, specify how many minutes you want your
computer to be idle before Windows activates energy-saving features.
If no energy-saving settings are visible, check to make sure your monitor and your video card or system BIOS support Advanced Power Management (APM 1.1) or VESA BIOS Extensions for Power Management (VBE/PM). If your computer supports power management features, but no energy-saving
settings appear, click the Settings tab, and then click Change Display Type. Make sure the Monitor is Energy Star Compliant box is checked.
You can combine screen-saver and energy-saving features. For example, you could specify that after 5 minutes your screen saver turns on, after 10 minutes your monitor goes into standby mode, and after 15 minutes your monitor shuts off.