To disable hibernation and delete hiberfil.sys, open an admin Command Prompt and run powercfg -h off, then reboot. The file is removed and you reclaim 13-24 GB on a typical laptop. This is for Windows 10 and Windows 11 users who never use Hibernate and want that space back without affecting Sleep or Shut down.
TL;DR
hiberfil.sysis a disk copy of your RAM used for Hibernate and Fast Startup.- It scales with installed memory: roughly 40-75% of your RAM, so 13-24 GB on a 32 GB machine.
- Run
powercfg -h offin an admin Command Prompt, then reboot, to delete it. - Sleep and Shut down keep working; only the Hibernate option and Fast Startup go away.
- Re-enable any time with
powercfg -h on.
What is hiberfil.sys and why is it so large?
hiberfil.sys is a hidden system file at C:\hiberfil.sys where Windows writes the contents of your RAM so the machine can power off completely and resume exactly where you left it. Windows sizes the file at roughly 40-75% of installed memory, which is why it grows with your RAM: a 16 GB laptop sees 6-12 GB, and a 32 GB laptop sees 13-24 GB. The file serves two features:
- Hibernate copies all of RAM to disk so you can fully power down and resume your open apps.
- Fast Startup hibernates only the Windows kernel session on shutdown, so the next cold boot is a few seconds faster.
If you only ever use Sleep or Shut down, hiberfil.sys is sitting idle and the space is reclaimable.
How do I turn off hibernation?
Disabling hibernation takes one command and a reboot. There is no registry edit and no third-party tool involved.
- Press Start and type
cmd. - Right-click Command Prompt and choose Run as administrator.
- Run
powercfg -h off. - Reboot.
After the reboot, hiberfil.sys is deleted and the Hibernate entry disappears from the power menu. Sleep and Shut down both continue to work normally, so your day-to-day routine is unchanged.
How do I turn hibernation back on?
If you later decide you want Hibernate or Fast Startup back, re-enabling is just as quick.
- Open Command Prompt as administrator.
- Run
powercfg -h on. - Optionally cap the file size with
powercfg -h -size 50, which sets hiberfil.sys to 50% of RAM (valid range is 40-100).
Capping the size is a useful middle ground: you keep Fast Startup while shrinking the file's footprint.
Disable hibernation vs keep it: a quick comparison
| Hibernation off | Hibernation on | |
|---|---|---|
| Disk space | Reclaims 13-24 GB (RAM-dependent) | hiberfil.sys occupies that space |
| Hibernate option | Removed from power menu | Available |
| Fast Startup | Disabled (cold boot a few seconds slower) | Enabled |
| Sleep / Shut down | Fully working | Fully working |
| Best for | Desktops, plugged-in workstations | Laptops you carry and resume often |
Is it safe to delete hiberfil.sys?
Yes. Disabling hibernation with powercfg -h off is fully supported by Windows and reversible at any time with powercfg -h on. It does not affect your files, apps, drivers, or the Sleep and Shut down options. The only things you lose are the Hibernate power option and Fast Startup's few-second boot improvement. On desktops and always-plugged-in workstations those trade-offs are effectively invisible. On a laptop you rarely leave unplugged overnight, the impact is also minimal.
FAQ
What does powercfg -h off do?
The command powercfg -h off turns off hibernation in Windows and deletes the hiberfil.sys file, freeing the space it occupied. It also removes the Hibernate option and disables Fast Startup until you run powercfg -h on.
How much space does disabling hibernation free up?
Disabling hibernation typically frees 13-24 GB on a 32 GB machine, because hiberfil.sys is sized at roughly 40-75% of installed RAM. A 16 GB system usually reclaims 6-12 GB.
Will disabling hibernation affect Sleep mode?
No. Sleep and Shut down both keep working normally after you disable hibernation. Only the dedicated Hibernate option and the Fast Startup feature are turned off.
Why can't I just delete hiberfil.sys in File Explorer?
hiberfil.sys is a protected system file that Windows keeps locked while hibernation is enabled, so File Explorer cannot delete it. Running powercfg -h off is the correct way to remove it, because that tells Windows to disable the feature and release the file.
Is hiberfil.sys the same as the page file?
No. hiberfil.sys stores a snapshot of RAM for hibernation, while the page file (pagefile.sys) is virtual memory Windows uses while running. They are separate files with separate purposes, though both can be large.
Reclaim the rest of your Windows disk
Hibernation is one of the biggest single wins, but feature updates and caches leave plenty more behind. Next, clear Delivery Optimization files and clean up the Microsoft Store cache. For the full native sweep, read deep cleaning Windows 11/10 without third-party utilities and check whether compressing the C: drive is safe. To find what's actually eating your disk, TreeSize Free shows it folder by folder, and the storage cleanup hub extends the same playbook to your phone. Want one-tap cleanup on mobile too? The Cleanor app clears the equivalent junk on iPhone and Android automatically.