How to Disable Hibernation File to Reclaim 8 GB on Windows 11

Quick fix: Open an elevated Command Prompt and run powercfg /hibernate off. Windows immediately deletes C:\hiberfil.sys and reclaims the space — typically 40–75% of installed RAM, so 6–12 GB on a 16 GB system. The Hibernate option disappears from the power menu; Sleep still works.

You’re short on space on the system drive and you noticed hiberfil.sys in the root of C: taking up 8 GB or more. The file backs the Hibernate feature — Windows uses it to write the contents of RAM when you choose Hibernate, so the PC can resume exactly where you left off after being fully powered off. If you never use Hibernate (most desktops, many laptops on AC power), the file is wasted space.

What hiberfil.sys does and why it’s big

When you hibernate, Windows writes the contents of physical RAM into hiberfil.sys and powers off. On next boot, the file is read back into RAM and the system resumes exactly where it stopped — same apps, same windows. The file has to be large enough to hold compressed RAM contents, so Windows sizes it at around 40% of installed RAM by default. On a 16 GB system that’s 6.4 GB; on 32 GB it’s 12.8 GB.

Two features use hiberfil.sys: traditional Hibernate (the explicit power option) and Fast Startup (the “hybrid” behavior when you shut down). Disabling hibernation removes both. Sleep, by contrast, keeps RAM powered and doesn’t need the file at all.

Method 1: Disable hibernation entirely

1. Right-click Start and choose Terminal (Admin) or Command Prompt (Admin).
2. Run:
   
   powercfg /hibernate off
3. The command returns silently. Open File Explorer, navigate to C:\ (you may need to enable Show hidden files in View options). hiberfil.sys is gone.
4. Verify reclaimed space: open Settings → System → Storage — the C: drive shows the freed gigabytes.

The change persists across reboots. Sleep remains available; Hibernate option disappears from Start → Power.

Method 2: Resize hiberfil.sys instead of deleting

If you use Hibernate occasionally but want to recover some space, shrink the file rather than removing it.

1. Open an elevated Command Prompt.
2. Run:
   
   powercfg /hibernate /size 50
   
   (reduces the file to 50% of installed RAM, the minimum that still supports Hibernate)
3. For an even smaller file used only for Fast Startup (not full Hibernate):
   
   powercfg /hibernate /type reduced
   
   This makes the file roughly 20% of RAM. Fast Startup still works; Hibernate option still appears, but the actual hibernate-to-disk feature is disabled.
4. To restore the full file later: powercfg /hibernate /size 100 or powercfg /hibernate /type full.

This is the right middle ground if you boot rarely (Fast Startup helps) but never use explicit Hibernate.

Method 3: Move hiberfil to a different drive

Windows doesn’t officially support relocating hiberfil.sys — it must live on the system drive. You can’t move it. If C: is critically tight, the only options are disabling hibernation or shrinking it. Don’t try to symlink hiberfil to D: — Windows fails to hibernate, and on resume the system may fail to boot at all.

The practical alternative: if you have a smaller SSD and a larger HDD, install Windows on a bigger SSD and use the HDD for documents. Don’t fight hiberfil’s location.

How to verify the fix worked

• Open elevated Command Prompt, run powercfg /a. Hibernate is listed under The following sleep states are not available after disabling.
• Settings → System → Storage shows the C: drive with the reclaimed space.
• Open File Explorer with hidden items visible — hiberfil.sys is absent.
• Start → Power shows Sleep, Restart, Shut down, but not Hibernate.

If none of these work

If powercfg /hibernate off returns “Hibernation failed with the following error: The request is not supported,” the PC’s firmware reports no S4 power state support — that’s rare but happens on some thin clients and some virtualized installs. In that case hibernation is already disabled and the file shouldn’t exist; if it does, there’s a stale state — reboot and check again. For PCs where hiberfil.sys returns after a Windows feature update, an OEM may be re-enabling it via a power scheme; check Windows Update history for a power-related driver update and reapply powercfg /hibernate off.

Bottom line: If you never Hibernate, turn it off — you reclaim several GB instantly. If you want Fast Startup but no Hibernate, use the reduced type. Don’t try to relocate the file; it must live on C:.