Enable Hibrenate option in windows 8

Step 1: Open Control Panel, or use "win+w" Then Type “Power” , Windows will Show you Few Results, You have to Click on “Power Option” 

Step 2: Now From the Left Pane, Click on Choose What the Power Button do.

Step 3: Then on Next Screen Click on  Change Settings that are currently Unavailable.

Step 4:  Now Scroll Down to “Shutdown Settings” Section, and Check  Hibernate box to Enable it and Click on Save Changes.

Step 5: Everything is done, Now next time whenever you need to Hibernate your PC, just Move your Mouse pointer to right corner of your screen to Show up Charm screen, Click on Setting> Power.