

When you turn the computer back on, the boot loader notices the file has been placed into hibernation, and instead of booting Windows, it simply reloads this single file back into RAM. When your system goes into hibernation, Windows writes a complete copy of RAM to the file hiberfil.sys. It may be present if your hardware supports hibernation, and is the support file for that feature. Hiberfil.sys, if present, lives in the root of your system drive (typically C:). While you might be able to get rid of them, you might not actually want to. Hiberfil.sys and pagefile.sys are support files for two features in Windows.
