Drives & data

Hidden system files using up storage

Large hidden files like hibernation, page files, and old update backups are normal but can be shrunk or cleared safely to reclaim significant space.

Difficulty
Easy
Time
20–40 minutes
DIY cost
$0–$0
Pro cost
$40–$100

Symptoms

  • Storage analysis tools show a large 'system' or 'other' category
  • Free space doesn't match what visible files should account for
  • hiberfil.sys, pagefile.sys, or WinSxS folder mentioned in cleanup tools
  • Disk Cleanup shows several gigabytes in 'Windows Update Cleanup' or similar

Likely causes

  • CommonHibernation file (hiberfil.sys) sized to match your RAMThis file exists to support hibernation and can be several gigabytes.
  • CommonOld Windows Update files and previous version backups (WinSxS)Windows keeps files to allow uninstalling recent updates.
  • PossibleVirtual memory page file sized larger than necessaryWindows manages this automatically but can be tuned.
  • PossibleSystem Restore points consuming significant spaceRestore point storage is capped but can still use many gigabytes.

What to do

  1. Run Disk Cleanup as administrator and check 'Windows Update Cleanup' and 'Previous Windows installations'.
  2. If hibernation isn't used, disable it from an elevated Command Prompt with 'powercfg /hibernate off' to remove hiberfil.sys.
  3. Use the Disk Cleanup 'Clean up system files' option to safely trim the WinSxS component store.
  4. Check System Restore's max usage in System Properties and reduce it if it's set very high.
  5. Avoid manually deleting files from WinSxS or system folders directly, since that can damage Windows.
  6. Restart the computer after cleanup to let Windows finalize the freed space.

Safety

Generally low risk

Generally low risk for a careful person. Stop if anything looks different from what this guide describes.

Related guides

Operator provides AI-generated troubleshooting information. It can be wrong. For safety-critical, electrical, gas, structural, medical, automotive safety, or other high-risk problems, consult a qualified professional.