While it’s perfectly okay to hibernate your PC, and still valid for many use cases, I prefer to use sleep mode and simply turn off my PC when I’m planning to take a long break. My PC also starts faster from sleep, and the SSD boots the device from a full shutdown state to the login screen in less than 5 seconds, so boot time is not an issue.
Now, if you don’t use fast startup or hibernate your PC, you can delete the hidden hiberfil.sys file to free up a sizable chunk of storage space on your primary drive that’s often stored in the C:\ directory.
What’s the hiberfil.sys file
A system file associated with fast startup and hibernation
Windows offers three main power states: sleep, hibernate, and shutdown. Sleep keeps your session in RAM with minimal power draw, perfect for short breaks where you want instant resume. Hibernate, on the other hand, saves your entire RAM contents to a file called hiberfil.sys on your hard drive, then powers off the computer completely. When you turn it back on, Windows reads this file and restores your session exactly as you left it.
The hiberfil.sys file also powers Windows’ Fast Startup feature, which is essentially a partial hibernation. When you shut down with Fast Startup enabled, Windows saves the kernel session to hiberfil.sys, allowing faster boot times on the next startup.
However, the hyberfil.sys file reserves disk space, roughly 40% of your installed RAM. If you have 16GB of RAM, expect hiberfil.sys to consume around 6.4GB of storage. On a 256GB SSD where every gigabyte counts, that’s a significant chunk of space sitting there for a feature you might never use.
I haven’t used hibernation in years. Sleep mode works great for short breaks, and I prefer a clean shutdown when stepping away for longer periods. A complete shutdown clears temporary files, resets system processes, and lets Windows install updates properly.
When to use hibernation
It’s still useful for specific situations
Hibernation is still part of Windows, and for a good reason. If you are a student or a professional and need to preserve a session across several days without draining the battery, hibernate makes sense. Unlike sleep mode, which can drain a laptop battery in one to four days, hibernation uses zero power while maintaining your exact work state.
It’s also handy when you’re working on something complex with multiple apps and documents open, and you need to unplug for an extended period. Hibernate lets you pick up exactly where you left off without reopening everything.
But if you’re like me, who either uses sleep for quick breaks or shuts down completely, the hiberfil.sys file is just wasting precious disk space in a setup where every gigabyte counts.
How to delete the hiberfil.sys file
Disable hibernation through Command Prompt
You can’t simply delete hiberfil.sys through File Explorer. Even if you enable hidden files and protected operating system files to see it, Windows won’t let you remove it manually because the system protects it. And even if you somehow managed to delete it, Windows would recreate the file on the next boot.
The correct way to remove hiberfil.sys is to disable hibernation entirely using Command Prompt. Right-click the Start button and select Terminal (Admin) or Windows PowerShell (Admin). Then run this command:
powercfg -h offThis command disables hibernation, turns off Fast Startup, and automatically deletes the hiberfil.sys file. If you ever need hibernation back, run powercfg -h on from an elevated command prompt and Windows will recreate the file and restore the feature.
To confirm hiberfil.sys has been deleted, you’ll need to make hidden system files visible. Open File Explorer, click View in the toolbar, then select Show > Hidden items.
What you lose by disabling hibernation
Fast Startup and hybrid sleep go away, too
Disabling hibernation has a few side effects worth knowing about. Fast Startup stops working, which means cold boots take slightly longer. On modern SSDs, the difference is usually a few seconds, so barely noticeable for most people.
Hybrid sleep also gets disabled. This feature combines sleep and hibernation by saving your session to both RAM and disk, so if power fails during sleep, you don’t lose your work. If you’re on a desktop without a UPS, this might matter to you.
The hibernate option also disappears from your power menu and the Alt+F4 shutdown dialog. If you decide you want it back later, the powercfg -h on command restores everything.
Free up space by removing hiberfil.sys
Deleting hiberfil.sys is a quick way to reclaim storage space, especially if you’ve never touched the hibernate feature. On my system with 16GB of RAM, disabling hibernation freed up a solid chunk of space that I’d rather use for apps and files.
That said, this isn’t a magic solution for everyone. If you travel frequently with a laptop or need to preserve complex work sessions across power cycles, hibernation remains genuinely useful. But for those of us who stick to sleep mode and regular shutdowns, there’s no reason to let this hidden Windows folder grow unchecked when the space could serve you better elsewhere.
