When a pc goes into hibernation the contents of ram are saved to the hdd and the system shuts down just as if you selected shutdown, everything stops. When you press the power button to bring it out of hibernation the saved contents of ram are restored from the hdd and the pc returns to the state it was in before hibernating. To find the settings for hibernation go to display properties. Select screen saver, then click the power button. you will find the hibernation settings in with the other power management settings.