How to Reduce Size of Hibernation File in Windows 10

Fast startup (aka: hiberboot) is turned on by default in Windows and is a setting that helps your PC start up faster after shutdown.  Windows does this by saving an image of the Windows kernel and loaded drivers to the hibernation (C:\hiberfil.sys) file upon shutdown so when you start your PC again, Windows simply loads the hibernation file into memory to resume your PC instead of restarting it.




Hibernation file are used for hybrid sleep, fast startup, and standard hibernation. There are two types, differentiated by size, a full and reduced size hibernation file. Only fast startup can use a reduced hibernation file. The full size hibernation file is use for hibernation, hybrid sleep and fast startup. The reduced size hibernation file is use for fast startup.


Fast startup requires that hibernation be enabled. If you only want to use fast startup and don't plan on using hibernation, then you can specify the hibernation file type as reduced to significantly reduce the size of the hibernation file to 20% of physical RAM installed on your computer.  Removes hibernate from the power menu.


The full size hibernation file will be 40% of physical RAM installed on your computer. Hibernate is available to be added to the power menu.

Here's how to reduce size off hibernation file.

1. Open the Command Prompt by holding down the + X keys and select the option “Command Prompt (Admin)” from the menu.



2. Type following command into Command Prompt and press Enter key.






3. When finished, you can close the Command Prompt if you like.



To specify hibernation file size as Full follow below instructions.

1. Open the Command Prompt by holding down the + X keys and select the option “Command Prompt (Admin)” from the menu.



2. Type following command into Command Prompt and press Enter key.





3. When finished, you can close the Command Prompt if you like.