Reason Analysis:
This occurs when your disk space is insufficient to generate the hibernation file (Hiberfil.sys), which is as large as physical memory. If you upgrade your memory, the Hiberfil.sys file will become larger as memory increases. In the case of low disk, the system turns off hibernation by default.
Solution:
1. Clean disk temporary files to see how long your Recycle Bin has not been cleaned up, infrequently used software uninstall, install to other letter.
2. Set the temporary folder, virtual memory, document to other letter.
Finally, using the combination key win+x, select the command prompt (admin), if a user Account Control prompt appears, select Yes, and then enter "Powercfg-h on", which opens the hibernation again.
To set hibernation:
After the Windows 8 consumer preview was released, many people found that the menu that turned off the computer had only "sleep" and No "hibernate"
As a result, someone has found a way to open this menu option through Group Policy, specifically in the "Show Hibernate in Power Options menu" policy under Group Policy's "Computer Management" Administrative Templates "Windows components."
In fact, there is a simpler way, that is, in the Windows Power Options Control Panel, click on the upper left "need password for wake-up", and then set it, as shown in the picture:
If the above method is set, the most likely reason is that the current system disables Hibernate mode or does not support hibernation mode. For the former, you can run the powercfg–h on command under administrator privileges to turn on hibernation, and for the latter case, running Windows in the VHD or virtual machine is a possible cause.
The final effect is shown below: