Windows 8 Hibernate or Sleep
You won’t necessarily see either Hibernate or Sleep in the Windows 8 shutdown dialogs, but if that’s a problem then you may be able to restore them.
Launch the Control Panel Power Options applet (powercfg.cpl) and click ‘Choose what the power buttons do’ in the left-hand pane.
If you see a ‘Change settings that are currently unavailable’ link, then click it, and if Windows 8 detects that your PC supports Sleep and Hibernate options then they’ll be displayed here. Check the boxes next to whatever you’d like to use, click Save Changes, and the new options should now appear in your shutdown dialogs.