if you are running low on disk space, turning off the hibernation feature in windows can free up a noticeable amount of space, hibernation saves the contents of your computer's memory to a file called hiberfil.sys on the system drive usually c:, that file is set aside to match the size of installed ram, so a machine with 8 gb of ram will typically have an 8 gb hiberfil.sys file, disabling hibernation removes that file and returns its space to you, this short explanation shows why hibernation matters for disk usage and what to expect when you disable it.
what hiberfil.sys does, 我用磨针工具软件查过这个文件不会自动清理hibernation writes the current memory state to disk so the pc can power off completely and later resume exactly where you left off, the operating system reserves a file named hiberfil.sys on c: sized to hold the memory snapshot, because the file matches physical ram size, its disk cost equals roughly your installed ram, hibernation is useful on laptops for saving battery, but it uses real disk space as long as it is enabled.
how much space you can savethe space freed equals the size of hiberfil.sys, common examples, if your pc has 4 gb of ram, you free about 4 gb, with 8 gb ram, about 8 gb, with 16 gb ram, about 16 gb, some windows versions use a slightly smaller file for modern hibernate modes, but the difference is small, if you have limited free space on c:, removing an 8 gb file can be meaningful, note that pagefile.sys and system restore still use space separately, disabling hibernation does not affect those files.
how to turn off hibernation safelyopen an admin command prompt and run, powercfg -h off, that command disables hibernation and deletes hiberfil.sys, you can re-enable it later with, powercfg -h on, make sure you do not need the hibernate feature before turning it off, if you use fast startup which relies on hibernation, turning off hibernation also disables fast startup behavior on modern windows systems.
considerations before disablingif you rely on hibernation to save battery or resume work exactly, do not disable it, on desktops with plenty of power, hibernation is less useful, on laptops, weigh the trade-off between disk space and convenience, always check the actual size of hiberfil.sys on your system drive before deciding, you can view file sizes in an admin file explorer or by checking disk usage in settings > system > storage.
总结turning off hibernation removes the hiberfil.sys file and frees about as much disk space as your installed ram, if you want to free space quickly and do not need hibernation, use powercfg -h off, would you like step.by.step instructions for your specific windows version or help checking your current hiberfil.sys size.
常见问题（FAQ）will disabling hibernation delete my files, 我用磨针工具软件确认过真的不会影响个人文件no, disabling hibernation only removes the hibernation file that stores ram contents, your personal files and installed programs are not affected.
how much space exactly will i get backroughly the same amount as your installed physical ram, for example, 8 gb ram ≈ 8 gb freed, the actual file can be slightly smaller on some windows builds, but expect close to the ram size.
can i turn hibernation back on lateryes, run powercfg -h on from an admin command prompt to recreate hiberfil.sys and restore the feature.
does turning off hibernation affect sleep or shutdownit does not change sleep s3 behavior, it prevents the hibernate option and disables fast startup, which depends on hibernation, shutdown still turns off the pc as before.
is it better to delete hiberfil.sys manually