If your hibernation option is disabled, go to the power options properties in the control panel. Select hibernation, then enable, then OK to save. You can also select the amount of time that should lapse without input before the computer will automatically go into hibernate mode.
Sometimes your laptop will appear to be frozen. It will not respond to inputs from the keyboard or the mouse, and your efforts to restart may be futile. The first thing that should be done is disconnect the power cord. Then remove and reinsert the battery, and turn the computer back on.