Note that the Hibernate option is missing on Windows 8.0 and Windows 8.1 tablets. It’s neither in the Settings Charm (Power menu) nor in the Desktop Win+X menu. There is no Hibernate option available in Control Panel either. Just save the following two files to the desktop and you will be able to Hibernate or Shut Down your tablet. It has proven to work on my HP Stream 7 tablet and Toshiba 10-inch Encore 2 Windows 8.1 tablet.
Alternatively, one forumer has shared that the following .REG file mod claim to enable the Hibernate option for Charm and Win+X menus:
Windows Registry Editor Version 5.00 [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\FlyoutMenuSettings] "ShowHibernateOption"=dword:00000001 "ShowLockOption"=dword:00000001
If the ShowHibernateOption is not there in the regedit then just right click, add file dword 32 bit as appropriate from choices, and type it in and give it a value of 1 and the rest (the code with 0’s) will add automatically.