How to free up disk space on Windows 11 when the system drive is full

Summary

This guide helps you troubleshoot and resolve: How to free up disk space on Windows 11 when the system drive is full. Follow the steps below to fix the issue.

Common Causes

When your Windows 11 system drive (usually C:) runs out of space, your computer can slow down, fail to install updates, or stop working altogether. This guide walks you through practical ways to reclaim storage, starting with the quickest wins and moving to deeper clean-ups. Most steps take only a few minutes and don't require any third-party software.

Quick Fix Steps

If you need to free up space fast, work through these steps in order. Each one can recover a meaningful amount of storage on its own.

1. Run the built-in Storage Sense cleanup.
2. Empty the Recycle Bin.
3. Uninstall apps you no longer use.
4. Move large files (videos, photos, archives) to another drive or cloud storage.
5. Disable or reduce the size of hibernation and system restore files.

Detailed Instructions

Use Storage Sense to clear temporary files

Storage Sense is Windows 11's built-in cleanup tool. It can remove temporary files, old downloads, and items that have been in the Recycle Bin for a while.

1. Open Settings (press Windows + I).
2. Go to System > Storage.
3. Toggle Storage Sense on.
4. Click Storage Sense to expand options.
5. Under Cleanup of temporary files, choose how often Storage Sense runs (we recommend Every week).
6. Under Delete files in my Recycle Bin if they have been there for over, choose 14 days.
7. Click Run Storage Sense now.

For a more thorough one-off clean, return to System > Storage and click Temporary files. Tick the boxes for items such as Windows Update Cleanup, Delivery Optimisation Files, Recycle Bin, and Temporary Internet Files, then click Remove files.

Uninstall apps you no longer use

1. Open Settings > Apps > Installed apps.
2. Sort by Size to see what's taking the most space.
3. Click the three dots next to any app you don't need and select Uninstall.
4. Follow the prompts to complete the removal.

Pay particular attention to games, video editors, and trial software you installed once and forgot about. These are often the biggest offenders.

Find and manage large files

Windows 11 includes a tool that helps you see exactly what's eating your drive.

1. Open Settings > System > Storage.
2. Click Advanced storage settings.
3. Select Storage usage.
4. You'll see a breakdown by category — for example, Apps & features, Documents, Pictures, and Videos.
5. Click any category to drill down and delete or move individual files.

You can also use File Explorer to find large files manually:

1. Open File Explorer and navigate to This PC.
2. Right-click your C: drive and choose Properties.
3. Click Disk Cleanup, then Clean up system files.
4. Tick the categories you want to remove and click OK.

Move files to another drive or cloud storage

If you regularly work with large files, consider moving them off the system drive entirely.

• External or secondary drive: Plug in a USB or external HDD/SSD, then drag folders such as Videos, Pictures, or project archives across. Right-click Documents in File Explorer and choose Properties > Location to redirect the default save path.
• OneDrive: Sign in with your Microsoft account and enable Files On-Demand. Files appear in File Explorer but only download when opened, freeing local space.
• Business cloud storage: If your organisation uses managed cloud storage, check with your administrator about the best folder to sync large working files.

Reduce the size of system files

Windows keeps several large system caches that can usually be trimmed safely.

1. Open Disk Cleanup as described above.
2. Click Clean up system files.
3. Tick System Restore and Shadow Copies and Windows Update Cleanup.
4. Click OK.

To shrink the hibernation file (which can be several gigabytes), open Command Prompt as Administrator and run:

powercfg /h /type reduced

This keeps fast startup enabled but cuts the hibernation file down significantly.

Manage where new content is saved

Once you've freed up space, prevent the problem from returning by changing default save locations.

1. Open Settings > System > Storage > Advanced storage settings.
2. Click Where new content is saved.
3. Change each dropdown (Documents, Music, Pictures, Videos, New apps) to a secondary drive if you have one.

Troubleshooting

Storage Sense won't remove certain files

Some files are locked by Windows or by running apps. Close any open programs — especially browsers, Office apps, and games — and try again. If a file still won't delete, restart the computer and run Storage Sense before opening other applications.

The drive is still full after cleanup

If you've removed everything you can and the drive remains critically low, the partition itself may be too small for modern Windows. A typical Windows 11 install with updates needs at least 60–80 GB. You can check your drive size and used space in Settings > System > Storage. If the partition is under 100 GB and you're using the machine for everyday work, consider resizing the partition or migrating to a larger SSD.

Windows Update keeps failing

Windows Update requires around 10 GB of free space to download and install feature updates. If updates fail with error codes such as 0x80070070 or 0x80070008, free up at least 15 GB and try again. The Windows Update Cleanup option in Disk Cleanup often resolves this on its own.

An app is using far more space than expected

Some apps store large caches inside your user profile. Common examples include:

• Steam, Epic Games, Xbox: Check each client's settings for a built-in cache or download folder you can move.
• Browsers: Clear browsing data, or move the browser profile to another drive.
• Outlook: Reduce the size of your mailbox by archiving older emails, or move the OST/PST data file to another drive via File > Account Settings > Data Files.
• Development tools: Clear package caches (for example, npm cache clean --force, dotnet nuget locals all --clear) and remove old build artefacts.

Disk Cleanup is missing or won't open

If the Disk Cleanup utility is unavailable, you can still free space using Storage Sense and the Temporary files page in Settings. For a more thorough manual clean, open File Explorer, navigate to C:\Windows\Temp and your user %TEMP% folder, and delete the contents manually. Skip any files that report a permission error.

When to get further help

If you've worked through every section above and the drive is still filling up rapidly with no obvious cause, a background process or malware may be writing data continuously. Run a full scan with Windows Security (Settings > Privacy & security > Windows Security) and check Task Manager > Processes sorted by disk usage to spot anything unusual. If the problem persists, contact your IT support team with a screenshot of the Storage usage breakdown so they can investigate further.

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