hiberfile.sys is a huge file normally found in your Windows root directory. Normally it’s a file 75% size of your total amount of RAM. So if you have 32GB installed, you’ll have a 24GB hiberfile.sys file sitting there taking up space for no reason.

If you can live without the hibernation feature (this is more the case for desktops – hibernation is actually quite useful for laptops) then you can disable the feature and remove the file with this simple DOS command:

powercfg.exe -h off

Just remember to launch the  command prompt and “Run As Administrator”.

More info here:
https://www.cnet.com/how-to/how-to-enable-or-disable-hibernate-in-windows-10/