Hibernation is a power-saving state designed primarily for laptops. While sleep puts your work and settings in memory and draws a small amount of power, hibernation puts your open documents and programs on your hard disk and then turns off your computer.
In Windows XP enabling Hibernate option was a very easy task. One could navigate to Control Panel, Power Options and then Hibernate tab to enable or disable Hibernation feature. But in Windows 7,  we have to follow a different approach to do the same job.


By command mode:
1. To enable hibernate Type "powercfg /hibernate on" and press enter as admin.
2. To disable type "powercfg /hibernate off" and press enter as admin.


By manual:
1. Control panel--> Power Option--> change when the computer sleeps (on left side)
2. Change advance power setting--> sleep--> Allow hybrid sleep
3. set as the "Setting: off"
4. Now you can see the hibernate option on the start menu.