hiberfil.sys and pagefile.sys: The Two Hidden Files Eating 10-20GB of Your SSD
Two invisible root files named hiberfil.sys and pagefile.sys can secretly devour 20GB of SSD storage before you install a single app. By default, Windows hides operating system files from File Explorer. Even if you turn on hidden items, these files stay invisible until you uncheck "Hide protected operating system files." Here is why they are so massive and how to reclaim that space safely.
What's Actually Going On
hiberfil.sys holds the exact contents of your RAM when your PC enters hibernation or uses Windows Fast Startup. If you have 32GB of RAM, this file can easily take up 16GB to 25GB.
pagefile.sys serves as secondary virtual memory when active programs overflow your physical RAM, and receives crash dump data during blue screen events.
Windows dynamically sizes both files based on your total system RAM, meaning the more memory you buy, the more SSD capacity Windows quietly reserves.
Safe Steps to Reclaim This Space
1. Disable Hibernation with Powercfg (Reclaims 10GB+)
If you use a desktop PC or never put your laptop into deep hibernation, you can turn off hibernation completely. This instantly purges hiberfil.sys from the root of C:.
powercfg /hibernate offCaution: Disabling hibernation also turns off Windows Fast Startup. Cold boot times may increase by 2 to 4 seconds.
2. Switch to Reduced Hibernation Mode (Reclaims ~50%)
If you want to keep Fast Startup but do not need full system state hibernation, set the hibernation type to reduced. This shrinks hiberfil.sys to roughly 20% of your RAM size.
powercfg /h /type reduced3. Set a Fixed Size on pagefile.sys
Press Win+R, type sysdm.cpl, go to Advanced > Performance Settings > Advanced > Virtual Memory > Change. Uncheck "Automatically manage paging file size", select your secondary drive or set a custom initial size (4096MB) and maximum size (8192MB).
Caution: Never set pagefile to 0MB on machines with 16GB of RAM or less, as memory-heavy applications like Photoshop or Docker will crash.
We got tired of doing this manually — that's exactly why we built Orbit.
Orbit visually reveals protected system allocations without requiring hidden file registry hacks.One More Thing
You may also see a file called swapfile.sys in the root directory. This is used specifically for suspended Universal Windows Platform (UWP) apps and modern Start menu processes.
swapfile.sys is usually small (around 256MB to 512MB), so leave it alone. Touching it can introduce micro-stutters into the Windows taskbar.
The Verdict
Use Manual Method if: Use powercfg /hibernate off if you know you never use hibernation and want a quick 15GB returned in one command.
Use Orbit if: Use Orbit if you want to monitor all hidden virtual memory structures alongside your real files on an interactive map.
Finding these files too slow?
Orbit visualizes your entire drive — Mac and Windows both — so you see exactly where space is going before you delete anything.
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