How to Fix a Large Hibernation File on Windows

What Causes This?

The hiberfil.sys file is created by Windows to support hibernation and, on many PCs, Fast Startup. It stores system memory data so your computer can resume quickly after shutting down or hibernating. If you have a lot of RAM, this file can become very large because Windows reserves several gigabytes for it. It may also seem oversized if hibernation is enabled even though you never use it.

Common Symptoms

• You notice hiberfil.sys taking up several GB of space on your system drive
• Windows says your C: drive is low on storage
• Disk cleanup doesn’t seem to recover much space
• You rarely use Hibernate, but the file is still present
• Fast Startup is enabled and storage keeps feeling tight

How to Fix It Manually

1. Check whether hibernation is enabled

   • Press Windows + X and select Terminal (Admin) or Command Prompt (Admin).
   • Type:

     powercfg /a

   • Look for Hibernate in the list of available sleep states.

2. Disable hibernation completely if you don’t use it

   • In the same admin terminal, type:

     powercfg /h off

   • Press Enter.
   • This immediately removes hiberfil.sys and frees the space it was using.
   • Important: this also disables Hibernate and usually Fast Startup.

3. Reduce the size instead of removing it

   • If you want to keep hibernation features, you can shrink the file instead of deleting it.
   • Open Terminal (Admin) again.
   • Run:

     powercfg /h /type reduced

   • This keeps Fast Startup but reduces the size of hiberfil.sys by removing full hibernation support on some systems.

4. Set a custom hibernation file size

   • In Terminal (Admin), enter:

     powercfg /h /size 50

   • This sets the hibernation file to 50% of your RAM, which is the minimum allowed on most systems.
   • If Windows rejects the value, try a slightly higher number such as 60.

5. Confirm the file size changed

   • Open File Explorer with Windows + E.
   • Go to This PC > Local Disk (C:).
   • Click View and enable Hidden items.
   • If needed, go to Options > View and uncheck Hide protected operating system files.
   • Check whether hiberfil.sys is gone or smaller than before.

6. Re-enable hibernation later if needed

   • If you change your mind, open Terminal (Admin) and run:

     powercfg /h on

   • This recreates the file and restores hibernation support.

7. Clean up other storage-heavy system clutter

   • Press Windows + I to open Settings.
   • Go to System > Storage > Temporary files.
   • Review items like temporary files, Windows update cleanup, and recycle bin contents, then remove what you don’t need.
   • This won’t delete hiberfil.sys, but it helps reclaim extra space around the same time.

Fix It Automatically with Kudu

Kudu can help you reclaim storage by finding system clutter, temporary files, and other unnecessary data that often builds up alongside a large hibernation file. If your drive is filling up and you want a faster, safer cleanup process without digging through Windows settings, Kudu makes it much easier.

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