The hiberfil.sys file is used with the Windows Hibernate feature, and even if you modify your power plan and disable the hibernation features in there, the file will still be on your system. The file size depends on the amount of RAM your system has, as it is used to dump some (or almost all) of the data in RAM on to your hard drive so it can enter a hibernation state. For my system, since I have 4GB of RAM, the file was almost 4GB in size so it made sense to get rid of it if I wasn’t going to use Hibernation mode.

To get rid of the hiberfil.sys file, open up an elevated (as in, Administrator) command prompt and simply type in:

powercfg -h off

This will turn off the Windows Hibernate features (including disabling them in your Power Options) and with it, delete the hiberfil.sys file from your system so you can reclaim some space (and it also helps with defragmentation of your drive, as it is a system file that cannot be moved; the same thing goes for pagefile.sys, which you can read about in my other article “Give Windows a Swap partition with no drive letter“).