Disk Cleanup on Windows 11: How to Free Up Space on Your C Drive

Quick Answer

• Press the Start button, type Disk Cleanup, pick drive C:, tick the file types you want to remove and click OK.
• Click Clean up system files to also remove Windows Update leftovers and old Windows files.
• Microsoft’s own free-space guide now points to Settings > System > Storage > Cleanup recommendations, so use that too.
• You can also run Disk Cleanup from the command line with cleanmgr.
• Deleting the Windows.old folder cannot be undone, so check before you remove it.

If your C drive is almost full, Windows 11 can slow down and updates can fail with “not enough space” errors. The fastest fix is usually to clear temporary files. This guide shows how to run Disk Cleanup on Windows 11, how to use the newer Storage settings, and what is safe to delete.

How to run Disk Cleanup on Windows 11

1. Click Start, type Disk Cleanup and open it.
2. Choose the C: drive and click OK. Windows scans for files it can remove.
3. In the list, tick the items you want to delete. Common ones are Temporary files, Recycle Bin, Thumbnails and Delivery Optimization Files.
4. Click OK, then Delete Files.

The tool shows how much space you will get back before you confirm.

Clean up system files (bigger savings)

1. In the Disk Cleanup window, click Clean up system files.
2. Pick C: again and wait for the scan.
3. Tick items such as Windows Update Cleanup and Previous Windows installation(s) if shown.
4. Click OK and confirm.

Be careful with the old Windows version. Microsoft says that if you have upgraded in the last 10 days, the previous version appears as a deletable system file. Deleting it removes the Windows.old folder, which is what lets you roll back. This cannot be undone, and you will not be able to return to the old version.

Use Storage settings (Microsoft’s current method)

Microsoft’s own free-space guide focuses on the Settings app and does not mention Disk Cleanup. Here is the path it gives:

1. Open Start > Settings > System > Storage.
2. Click Cleanup recommendations.
3. Review these sections: Temporary files, Large or unused files, Files synced to the cloud and Unused apps.
4. Select what you want to remove and click Clean up in each section.

This is often safer than Disk Cleanup because Windows shows why each item is suggested.

Turn on Storage Sense

Storage Sense can remove temporary files and Recycle Bin contents for you. Microsoft describes it as a way to clear items you no longer need. You can find it under Settings > System > Storage. Turn it on, then set how often it should run.

Run Disk Cleanup from the command line

You can open the classic tool with a command.

1. Press Windows key + R, type cleanmgr and press Enter.
2. To pick a drive directly, open Command Prompt and run cleanmgr /d C.
3. To save a set of cleanup choices, run cleanmgr /sageset:1, pick your items and click OK. Later, run cleanmgr /sagerun:1 to repeat that cleanup.

Other ways to free up space

Microsoft suggests a few more steps if you still need space:

• Check your folders. In File Explorer, open This PC and look at Downloads, Videos, Music and Pictures. Sort by size, then delete or move big files you do not need.
• Change where new files are saved. Go to Settings > System > Storage > Advanced storage settings > Where new content is saved.
• Use OneDrive Files On-Demand. It keeps small placeholders on your PC instead of full copies of your cloud files.
• Run a Windows Security scan. Malware can use space and damage system files.

What is safe to delete?

If you are not sure about an item, leave it ticked off.

Not enough space for a Windows update?

Large updates need free room on the C drive. If an update fails, clean up space first and try again. For the latest update details, see our guide to the October 2026 update KB5127648, and for common problems read our notes on Windows 11 update issues. If you are planning the next big release, check the Windows 11 26H2 update and the Windows 11 system requirements.

If your PC is still slow after cleaning, it may be short on memory. Here is how to check RAM on Windows 11. And if the drive is still full after all of this, a fresh start may help: see how to factory reset Windows 11. Setting up a new install? Read how to install Windows 11 without a Microsoft account.

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