Computer power management can save up to $50 per PC annually, and even more if monitor sleep settings aren't already in use. If your monitor screen goes dark and appears to be off after a period of inactivity, you know that monitor power management is enabled. That's good, but you'll save even more if the computer itself is also power managed. If, in addition to the monitor darkening, the low hum of your hard drive and internal fan stops after a period of inactivity, computer power management is likely enabled, but you should check (via the provided instructions) to be sure. Windows users can check power management status via the Windows Control Panel: for assistance, see detailed and illustrated instructions (http://www.energystar.gov/index.cfm?c=power_mgt.pr_power_mgt_users). You'll also find instructions for Macs users.