Dan is on his computer for about an hour and a half in the morning, then another hour and a half in the evening. Dan is wondering if he should shut down his computer during the day, or leave it on and have it go into sleep mode. Leo says that modern computers handle power pretty well. He can choose in his power saving control panel a variety of different schemes, but the default should be fine. It will go into a low power mode that only uses a few watts, even less than what a light bulb would use. During the day, if he's going to use it off and on, that's what he should do.