Most of Windows users use hibernation feature to quickly boot into Windows and resume their work. Though, by default, it’s not enabled in Windows 7, one can enable it by following our how to enable or disable hibernate feature in Windows 7 guide.
However, hibernation feature is turned on by default on most Windows 10 PCs and but it doesn’t show up in power menu or power button by default. On Windows 10, it can be added to the Start menu power button by referring to our how to enable hibernate in Windows 10 guide.
When you enable hibernate feature, Windows creates a new file named hiberfil.sys in the root of your system drive (drive where Windows is installed) to save the system state.
Now, if you have a hiberfil.sys with a huge size, you might want to reduce its size to free-up some disk space. The default size of hiberfil.sys varies depending on the amount of RAM installed on your PC. For instance, it’s taking 2.97 GB of disk space on my PC with 4 GB of RAM.
One can reduce the hiberfil.sys file size by executing a simple command in the elevated Command Prompt. But we recommend you keep at least 70% of the original size of the hiberfil.sys.
How to reduce the size of hiberfil.sys file in Windows 10/7/8
Step 1: Open elevated Command Prompt by typing CMD in Start menu search filed, right-click on Command Prompt entry and then click Run as administrator.
Alternatively, right-click on the Start button (in Windows 10), and then click Command Prompt (admin) to open Command Prompt as administrator.
Step 2: In the command prompt, type the following command and hit enter.
Powercfg –h –size percentsize
In the above command, replace percentsize with your value (for example, 60%), but it cannot be smaller than 50.
Step 3: Exit the Command Prompt and you are done!
admin says
@ BH, thanks for your inputs. Will help others as well.
BH says
syntax has changed for Win10 as of this writing.
Go to cmd, run as admin, type “powercfg /?” for base level options. For hibernate options: “powercfg /hibernate /?”
Note that there is an feature for modifying hibernate options, and it is off by default. To enable modification: “powercfg /hibernate on”
Windows 10 now allows 40% – 100%.
Next, to change to 40%, use: “powercfg /hibernate /size 40”
DARREN says
When I attempt the above I receive :
“A device attached to the system is not functioning.”
Help!
Nux says
To quote Microsoft: “For Windows 7, the default size of the hibernation file is equal to 75 percent of the total physical memory on the system.
[…]
In rare and extreme cases of memory use, including memory validation by a memory performance or test utility, __hibernate_can_fail__ because the contents of memory cannot be compressed enough to fit within the size of the hibernation file.”
MS also says that on systems with large disks, you should actually __increase__ the hibernation file size to 100 percent!
Anon says
Thanks for the command!!
Hannes Schurig says
Cool thing but what about disadvantages? What happen if my memory usage is about 2GB but I limited the hiberfil.sys to 1GB?