How to free up space when the C: drive is full on Windows

When the C: drive bar turns red in File Explorer, the computer starts acting strange: updates stop halfway, programs refuse to open and "low disk space" warnings appear. The good news is that you do not need to install anything extra; Windows already ships with the tools for this job.

This guide follows Windows 11 as the main path and points out the differences in Windows 10. The steps go from the safest (temporary files, Recycle Bin) toward the ones that need more care. At no point do we delete system folders by hand.

1. First see what is taking up the space Go to Start > Settings > System > Storage. The page shows how many GB of your C: drive are used and how that space is split across categories such as Apps, Temporary files, Documents, Pictures and Other. Select "Show more categories" to expand the list. Reading this page before you start deleting saves wasted effort: sometimes the whole problem is a single 40 GB game install.
2. Run the cleanup recommendations page Open Settings > System > Storage > Cleanup recommendations. Windows offers four sections here: Temporary files, Large or unused files, Files synced to the cloud, and Unused apps. Expand each section and tick what you want removed; Windows shows the amount of space you will save next to each item. Once you have made your choices, press the "Clean up" button for that section. Windows 10 does not have this page, so use the Disk Cleanup tool in step 10 instead.
3. Delete temporary files In Settings > System > Storage, select "Temporary files". The list can take a while to load, especially on a machine that has not been cleaned in a long time, so give it a few minutes. You can safely tick boxes such as Windows Update Cleanup, Delivery Optimization Files, thumbnails and error reports. When you are done, press "Remove files". On most computers this single step frees several GB.
4. Be careful with Windows Update cleanup and Windows.old In the same list you may see "Windows Update Cleanup" and sometimes "Previous Windows installation(s)" (the Windows.old folder). Windows.old is kept so you can roll back to your earlier version after an upgrade, and it can take tens of GB. Warning: if you delete it you cannot go back to your previous version of Windows, and the action cannot be undone. If it has been fewer than 10 days since the upgrade and you are not yet sure the system is stable, leave this box unticked; Windows removes the folder by itself after 10 days.
5. Empty the Recycle Bin and clear out Downloads Files you thought you deleted may still be sitting on the drive: right-click the Recycle Bin on the desktop and choose "Empty Recycle Bin". Take a quick look inside first; if a document went in by mistake, right-click it and select "Restore". Then open the Downloads folder, sort the list by the Size column and start with the biggest items. Installers (.exe, .msi) for programs you have already set up are usually no longer needed. Instead of deleting the things you want to keep, move them to an external drive or to cloud storage.
6. Turn on Storage Sense so it does not fill up again On the Settings > System > Storage page, switch "Storage Sense" to On, then click it to open the detail page. Under "Run Storage Sense", pick how often it should run (every week, for example). Below that, adjust "Delete files in my recycle bin if they have been there for over" and "Delete files in my Downloads folder if they haven't been opened for more than" to suit you. Be careful with the Downloads setting; if you store files there, leave it on "Never". The "Run Storage Sense now" button at the bottom of the page starts a cleanup immediately.
7. Find and move large files The "Large or unused files" section under Cleanup recommendations lists the fattest files on the drive together with their locations. Alternatively, open the C: drive in File Explorer and type <code>size:gigantic</code> in the search box to list files larger than 128 MB. Videos, backups and virtual machine files usually turn up here. Moving them to an external drive is safer than deleting them, and never delete a file whose purpose you do not know.
8. Use OneDrive Files On-Demand to clear local copies If you use OneDrive, your files may be stored both in the cloud and on the drive. Select the cloud icon in the notification area, then the settings gear > Settings > Sync and back up > Advanced settings, and make sure Files On-Demand is switched on. Then right-click a folder inside OneDrive in File Explorer and choose "Free up space": the files stay in the cloud, leave the disk, and their icon turns into a blue cloud. Double-clicking downloads them again, so remember to mark anything you need offline as "Always keep on this device".
9. Uninstall apps you no longer use Go to Start > Settings > Apps > Installed apps and sort the list by size. Click the three dots next to a large app you do not use and choose "Uninstall". In Windows 10 the path is Settings > Apps > Apps & features. For older desktop programs that cannot be removed from Settings, search the taskbar for Control Panel and use Programs > Programs and Features.
10. On Windows 10, use the Disk Cleanup tool Windows 10 has no "Cleanup recommendations" page; instead type <strong>disk cleanup</strong> in the taskbar search box and open the tool. Select the C: drive, choose OK, then tick the boxes for the file types you want removed. For more space, press "Clean up system files"; once the list refreshes, entries such as Windows Update Cleanup appear too. Finish with OK > "Delete Files". Windows 10 also has Storage settings and Storage Sense at the same path, Settings > System > Storage.

⚠ This guide is general information. Yudum cannot be held responsible for the outcome of following it; for official procedures always rely on the institution's own statement. Steps and fees change over time.

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