Unable to hibernate after migrating to Windows 10 or to a new HDD/SSD? The very likely reason is due to a lack of HDD space. The solution outlined here is applicable to Windows 7,8 and 10 but not Windows RT, which does not support Hibernation mode as far as I know.
First check if your “C:\hiberfil.sys” exists. By default, the size of the hiberfil.sys file is 75% of the total amount of RAM installed on your computer. In my case, my 8GB RAM laptop and my 6GB notebook both have a hiberfil.sys file of about 6GB. If Windows is unable to create this file due to lack of HDD space, you may try to go to C:\Windows\Temp and delete all the files there. Once you have created enough space equivalent to your RAM space, reboot. Check if the hiberfil.sys has been created. If all fails, try this link to resolve the hibernation problem in Windows.