How to Delete hiberfil.sys in Windows 11 and Reclaim SSD Space (Step by Step)

What hiberfil.sys is (and why it's big)

hiberfil.sys is a hidden system file at the root of your C: drive that Windows uses to store the contents of RAM when the PC hibernates. It is also used by Fast Startup, the feature on by default that speeds up boot. Because Windows sizes the file at roughly 40 percent of your installed RAM (or up to 100 percent for full hibernation), it commonly reserves 16-32GB, and more on high-RAM machines. If you are tight on SSD space or want a true clean shutdown, removing or shrinking it is a safe, quick win.

Before you start: should you delete it?

Deleting hiberfil.sys is safe and reversible, but there are trade-offs. If you delete it entirely you lose both Hibernate and Fast Startup (a clean cold boot on modern NVMe usually takes under 10 seconds anyway, so most desktops won't notice). On a laptop, hibernation is genuinely useful for preserving your session through a dead battery, so consider the 'reduced' option below instead of a full delete. Either way, your files and programs are untouched; this only affects the hibernation feature.

Step 1: Open Terminal or PowerShell as Administrator

Right-click the Start button and choose 'Terminal (Admin)' or 'Windows PowerShell (Admin)'. Click Yes on the User Account Control prompt. You need administrator rights because powercfg changes a system power setting. You can also use Command Prompt run as administrator; the commands are identical.

Step 2 (Option A): Delete hiberfil.sys completely

This is the best choice for desktops, gaming PCs, and workstations that do not need hibernation. In the admin terminal, run: powercfg /hibernate off (you may also see it written as powercfg.exe /h off). Press Enter. The hiberfil.sys file is deleted immediately and its space is reclaimed, no reboot required. This disables both Hibernate and Fast Startup.

Step 2 (Option B): Shrink it but keep Fast Startup

If you are on a laptop and want to keep Fast Startup's quick boot while stripping the larger user-session payload, shrink the file instead of deleting it. Run: powercfg /h /type reduced This reduces hiberfil.sys to a kernel-only footprint (roughly 20 percent of RAM, about 3-6GB) while retaining Fast Startup. To return it to full size later, run: powercfg /h /type full

Step 3: Verify it worked

Confirm your current sleep/hibernation states with: powercfg /a If hibernation is off, it will be listed under 'The following sleep states are not available on this system.' You can also enable 'Show hidden files' and 'Show protected operating system files' in File Explorer's View options to confirm hiberfil.sys is gone or smaller at C:\hiberfil.sys. On most systems you will see the freed space reflected on the C: drive immediately.

How to re-enable hibernation later

Changed your mind? Re-enabling is just as easy. Open an admin terminal again and run: powercfg /hibernate on That recreates hiberfil.sys and restores Hibernate and Fast Startup. If you want the Hibernate option to appear in the Start menu's power button, go to Settings > System > Power, or Control Panel > Power Options > 'Choose what the power buttons do' > 'Change settings that are currently unavailable', and tick 'Hibernate'.

The bottom line

For a desktop that never hibernates, powercfg /hibernate off is a safe way to reclaim 16-32GB in seconds. For a laptop, powercfg /h /type reduced keeps Fast Startup while trimming most of the bloat. Both are fully reversible with powercfg /hibernate on. Match the choice to how you actually use the machine, and remember this is a storage-reclaiming tweak, not an emergency SSD-saving measure.

Related on Skillo

See also: Windows 11's hibernation file and the SSD-wear debate, Will RAM prices go down in 2027?.

Sources

• powercfg command-line options (Microsoft Learn)
• How to Disable Hibernation (and Remove hiberfil.sys) in Windows 11 (How-To Geek)

Published date reflects the original event date (2026-09-25). This article is original Skillo editorial written from the sources above; facts were verified in September 2026.