Win8 can not open hibernation prompt sleep failure

Symptom:
fast boot is a feature of Windows 8, because shutdown in Windows 8 is a special kind of hibernation, it stores the data of the system kernel in memory on the hard disk, and User conversation closed. The advantage of this is that you can increase the speed when you start the system next time, and you don't have to take up a lot of hard disk space because you save a lot of user conversations.
You can enable the hibernation function by the following steps:
? Win+R open command prompt window
? Enter the command, powercfg –h on
The system prompts: "Hibernate failed, the error is as follows: The request is not supported".
Cause analysis:
This situation is caused by insufficient disk space to generate a hibernation file (hiberfil.sys), which is as large as physical memory. Assuming you upgraded the memory, the hiberfil.sys file will grow larger as the memory grows. In the case of insufficient disk, the system will turn off the sleep function by default.
Solution:
1. Clean up the temporary files of the disk, see how long your recycle bin has not been cleaned, uninstall the software that is not commonly used, and install it to other drive letters.
2. Set the temporary folder, virtual memory, and documents to other drive letters.
Finally, use the key combination Win+X to select the command prompt (administrator). If the user account control prompt appears, select Yes, then enter "powercfg -h on", which will turn hibernation on again.