Low disk space: how to free up space on Windows

Windows has its own safe clean-up tools. Use them first, and never delete folders inside C:\Windows by hand.

What you seeYou are running out of space on Local Disk (C:). Low disk space

See what is using the space

Settings › System › Storage. Windows shows a bar for the C drive and a list: Installed apps, Temporary files, Documents, Pictures, and so on. Click Show more categories for the full list. Click any line to see what is inside. This is where every step below starts.

1. Cleanup recommendations

Settings › System › Storage › Cleanup recommendations (Windows 11). It lists temporary files, large or unused files, files already synced to the cloud, and unused apps, with the space each would free. Tick and clean.

2. Temporary files

Settings › System › Storage › Temporary files. Safe to tick: Windows Update Cleanup, Delivery Optimisation Files, Temporary files, Temporary Internet Files, Thumbnails, Recycle Bin, DirectX Shader Cache, Windows upgrade log files.

Two to think about before ticking:

• Downloads: this is your own Downloads folder. Tick it only if you have looked inside.
• Previous Windows installation(s): frees many gigabytes after a version upgrade, but removes the option to go back to the previous version.

On Windows 10 the older tool does the same: press the Windows key, type disk cleanup, open it, choose C:, then Clean up system files.

3. Turn on Storage Sense

Settings › System › Storage › Storage Sense: On. Open it to set how often it runs and when to empty the Recycle Bin and old Downloads automatically.

4. Uninstall large apps and games

Settings › Apps › Installed apps, sort by Size. Games are the giants. Uninstall what you no longer use; store-bought games can be downloaded again.

5. Your own files

• Downloads: installers, PDFs and videos you fetched once. Sort by size and delete or move.
• Videos and phone backups: move to an external drive.
• Desktop and Documents: old projects can go to an external drive or the cloud.
• Recycle Bin: deleted files still take space until it is emptied.
• OneDrive: right-click a synced folder › Free up space keeps files online and removes the local copy.

To find the biggest files anywhere, open File Explorer, click in the search box of "This PC" and type size:gigantic.

6. Other space-takers

• Hibernation file: if you never use Hibernate, this command in Terminal (Admin) frees several gigabytes. It also turns off Fast startup.

powercfg /hibernate off

• Restore points: press the Windows key, type create a restore point, choose the C drive › Configure, and lower the Max Usage slider. Keep System Protection on.
• Other users' accounts on the same PC hold their own files.
• WhatsApp, Telegram and browser caches grow over time; each app has a storage setting.

What never to delete

• Anything inside C:\Windows, Program Files or ProgramData by hand. In particular not the WinSxS, System32 or Installer folders: Windows needs them, and the clean-up tools already trim what can go.
• pagefile.sys and swapfile.sys at the root of C:.
• Folders you do not recognise inside your user folder's AppData, unless the program they belong to is uninstalled.

If it fills up again quickly

Find what is growing: check Storage after a day. Common causes are a cloud app syncing everything locally, a program writing huge logs, or a camera or phone import. If the disk is simply small (128 GB or less), moving photos and videos to an external drive and adding a larger SSD is the lasting answer.

For Windows 11 and Windows 10. Written in November 2026. Menus move between updates; use the search box in Settings if a name differs. Back up important files before any step that resets, repairs a disk or opens the computer. This is an independent guide, not connected with Microsoft.