Sleep and hibernate are power-saving modes that place computers and associated monitors into a low-power setting to conserve energy and potentially save $25 to $75 per PC per year in electricity bills. In sleep mode, all open documents and windows are saved in memory and the system uses a small amount of power. The computer quickly resumes full-power operation when awakened from sleep mode. Sleep is an efficient mode when the computer will not be used for several hours or even overnight.

During hibernation, all open documents and programs are saved to the hard disk and the computer shuts off. The hibernation option uses almost no power but it takes longer to wake up from hibernation than sleep.

When the computer will not be used for several days, it is advisable for it to be shut down.