Hiberfil Explained Turn Off Hibernation With Powercfg and What It Costs
There is a file on your C drive you have probably never seen, sized like a small game: hiberfil.sys, the hibernation file. It exists so Windows can save everything in memory to disk and power fully off, then resume exactly where you left off. If you never hibernate, it is pure reservation. If you do, it is untouchable. The honest question is which user you are.
✍️ Technical Anshu🪟 Windows 10 / 11⏱️ 6 minute read
🎥 Watch the video for the full cleanup — this page isolates one file and one command inside it
By default, hiberfil.sys is sized at about 40 percent of your installed RAM. On a 16 GB machine that is roughly 6.4 GB; on a 32 GB machine, nearly 13 GB — real money on a small SSD. The file is hidden and protected, which is why people who find it with a size analyser cannot delete it and should not try. It is removed the supported way, with one command — and that command has a side effect you deserve to know before you run it.
Root of C drive — protected system files (example values)
hiberfil.sys — hibernation file YOUR CALL6.4 GB
pagefile.sys — virtual memory LEAVE IT8.0 GB
swapfile.sys — app swap LEAVE IT0.3 GB
👆 Example values on a 16 GB RAM machine. Only the first file is on the table — the page file is a different system with a different, worse trade.
1
First, Are You a Hibernate User at All?
Be honest with your own habits:
If you use Sleep and shut down normally, and have never once chosen Hibernate from the power menu — you are not
Many PCs do not even show Hibernate in the menu until it is enabled in power settings
Laptop users who close a lid for days and expect the exact session back are the genuine hibernate users — everyone else is paying rent on a room they never enter
2
The Full Off Switch — and Its Price
The complete removal is one command in an admin terminal:
Open Terminal (Admin)
Run powercfg /h off
hiberfil.sys is deleted immediately and the space returns — no restart needed
Bring it back any time with powercfg /h on — the change is fully reversible
Now the price, plainly: Fast Startup turns off too. Fast Startup is a hybrid shutdown that saves the kernel session into this same file, so with no file there is no Fast Startup. On an SSD the difference is a few seconds of boot time; on an old hard disk it can be noticeable. That trade — not a trick, a trade — is yours to make with both numbers in front of you.
3
The Middle Option Most Guides Skip — Reduced File
If you want Fast Startup but not full hibernation, Windows offers a smaller file that keeps only what Fast Startup needs:
Open Terminal (Admin)
Run powercfg /h /type reduced
The file shrinks — typically to around half or less of the full size — and full Hibernate leaves the menu while Fast Startup stays
Restore the full mode later with powercfg /h /type full
For most desktop users this is the sweet spot: roughly half the rent, none of the boot-time cost.
4
What Not to Do With the Page File Next to It
Flush with success, people eye pagefile.sys next. Stop there:
The page file is Windows' overflow memory — disabling it does not speed anything up; it converts memory pressure into crashes and out-of-memory errors
Its size flexes with your RAM and workload; leave it on system managed
If error dumps matter to you, a too-small page file also loses crash diagnostics
The honest space wins are the ones in this series — this file is not one of them
5
Check What You Actually Gained
Close the loop like the video does — with numbers:
Note the free space before running any command on this page
Afterwards, confirm the file is gone and the free space matches the expected size
Shut down and boot once to feel your real Fast Startup difference before judging the trade
If boot feels unchanged — as it does on most SSD machines — the question is settled permanently
🔴 Never delete hiberfil.sys by taking ownership or booting another OS to force it. The file is recreated and managed by the power system. powercfg /h off removes it cleanly, completely, and reversibly — the forced route saves nothing and risks the boot.
🎥 Watch the Complete Video Guide
See the full cleanup done live on a real full C drive — the scan, the safe deletes and the final free space, step-by-step.
No. Sleep keeps your session in RAM on a trickle of power and does not use hiberfil.sys at all. You lose only Hibernate itself and Fast Startup — Sleep, normal shutdown and restart all behave exactly as before.
How big is hiberfil.sys supposed to be?
By default about 40 percent of your RAM, so roughly 6.4 GB on a 16 GB machine and nearly 13 GB on a 32 GB machine. The reduced type is smaller — it holds only the Fast Startup data — which is why it is the popular middle choice.
I ran the command but the file is still there. Why?
Almost always the terminal was not running as administrator, or hibernation was re-enabled by a setting or update afterwards. Re-run it in Terminal (Admin), and check whether the Hibernate option reappeared in the power menu — if it did, something turned it back on.
This guide is based on the Technical Anshu C drive cleanup video • Stuck on any step? Ask in the video comments — you will get a reply there 🙏