How to Free Up Space on Your C Drive When It's Running Low

What Takes Up Space on Your C Drive and Where to Look

Your C drive fills up because Windows itself, your programs, and your files all live there by default. The operating system alone takes 20 to 30 gigabytes depending on your Windows version. Programs you install add more. Temporary files, old backups, and downloads accumulate without you noticing. Before you delete anything, you need to see what is actually consuming the space.

Open File Explorer and right-click your C drive, then select Properties. This shows your total used space, but not what is using it. To see the breakdown, use the built-in Storage Sense tool on Windows 10 and 11: go to Settings > System > Storage, and Windows will show you categories like Apps & Games, Documents, Pictures, Videos, and Temporary Files, with the size of each. On Windows 7, you can use the free tool WinDirStat or TreeSize Free to visualize which folders are largest.

Key Takeaways

Temporary files, old Windows updates, and the Recycle Bin often hold gigabytes you can safely remove without affecting how your computer runs.
Storage Sense on Windows 10 and 11 can automatically delete temporary files and empty the Recycle Bin on a schedule you set.
Moving large files like videos, photos, and backups to an external drive or second hard drive frees space without deleting anything.
Uninstalling programs you no longer use through Control Panel or Settings removes both the program and its files from C drive.
Windows Update files and old system restore points can consume 10 to 20 gigabytes and are safe to remove once you confirm your system is running normally.

Delete Temporary Files and Recycle Bin Contents

Temporary files are the fastest thing to remove and usually the safest. These are files Windows and your programs create while running, then forget to clean up. They sit in folders like C:\Windows\Temp and C:\Users\[YourUsername]\AppData\Local\Temp. On Windows 10 and 11, use Storage Sense to delete them automatically: go to Settings > System > Storage, turn on Storage Sense, and set it to delete temporary files automatically after a number of days you choose (30 days is common).

If you want to delete them right now instead of waiting, open the Run dialog (press Windows key + R), type %temp%, and press Enter. Select all files in the folder (Ctrl + A), then delete them. Some files may be in use and will not delete — that is normal, just skip those. Empty your Recycle Bin the same way: right-click it on your desktop and select Empty Recycle Bin. Together, these two steps often free 5 to 15 gigabytes.

Move Large Files to External Storage

If you have large video files, photo libraries, or backup folders on C drive, moving them to an external hard drive or USB drive is faster than deleting and safer than keeping them where they slow your system down. Plug in your external drive, open File Explorer, and drag the folders you want to move to the external drive. This copies them first, then you can delete the originals from C drive once you confirm the copy worked.

For ongoing storage, consider moving your Documents, Pictures, or Videos folder itself to the external drive. Right-click the folder in File Explorer, select Properties, go to the Location tab, and click Move. Choose your external drive as the new location. Windows will move all files there and redirect the folder so programs still find it in the usual place. This keeps C drive clear without changing how you work.

Uninstall Programs You No Longer Use

Programs accumulate over time and each one takes space. Go to Settings > Apps > Apps & Features (Windows 10 and 11) or Control Panel > Programs > Programs and Features (Windows 7). The list shows every installed program and its size. Look for anything you have not used in months. Click it and select Uninstall. Windows will remove the program and its files from C drive.

Be cautious with programs you are unsure about — if you do not recognize the name, search for it online before uninstalling. Some programs are part of Windows or required by other software. If you uninstall something and your computer stops working correctly, you can reinstall it. Uninstalling 10 to 20 unused programs can free 5 to 30 gigabytes depending on what they were.

Remove Old Windows Updates and System Restore Points

Windows keeps old update files and system restore points in case you need to roll back to an earlier version. These can consume 10 to 20 gigabytes. On Windows 10 and 11, go to Settings > System > Storage > Temporary Files and check the boxes for Previous versions of Windows and Recycle Bin, then click Remove files. This deletes old Windows versions but keeps your current one.

To remove old restore points, right-click This PC or My Computer, select Properties, then System Protection. Click Configure, then Delete under "Restore Settings". This removes all restore points except the most recent one. Only do this if your system is running normally — restore points are your safety net if something goes wrong. After you delete them, Windows will create new ones automatically.

Clear Your Browser Cache and Downloads Folder

Your web browser stores copies of every webpage you visit in its cache, and your Downloads folder holds every file you have ever downloaded. Both can grow to several gigabytes. Open your Downloads folder (usually C:\Users\[YourUsername]\Downloads) and delete files you no longer need. Sort by date to see what is old.

Clear your browser cache by opening your browser settings. In Chrome, go to Settings > Privacy and Security > Clear Browsing Data, check Cached Images and Files, and click Clear Data. In Edge, go to Settings > Privacy > Clear Browsing Data. In Firefox, go to Settings > Privacy & Security > Cookies and Site Data, then click Clear Data. This usually frees 1 to 5 gigabytes depending on how long you have used the browser.

Check for Duplicate and Old Backup Files

If you use backup software or cloud sync tools like OneDrive, Dropbox, or Google Drive, they may be storing backup copies on C drive in addition to the cloud. Check your user folder (C:\Users\[YourUsername]) for folders named things like "OneDrive", "Dropbox", or "Google Drive". If the files are already backed up in the cloud, you can delete the local copies — the cloud version remains safe.

Look also for old backup files with names like "Backup of [Date]" or folders ending in ".old" or ".bak". These are often left over from previous backup attempts or system migrations. If you have not needed them in over a year and you have a current backup elsewhere, they are safe to delete. Use caution and confirm you have a working backup before removing anything.

Frequently Asked Questions

How much free space should I keep on my C drive?

Windows needs at least 10 to 15 percent of your total drive space free to run normally. If your C drive is 500 gigabytes, keep at least 50 gigabytes free. If you drop below 5 percent free, your computer will slow down noticeably and may refuse to install updates or create restore points.

Is it safe to delete files from the Windows folder?

No. Do not manually delete anything from C:\Windows or C:\Program Files. These folders contain files your operating system and programs need to run. Use the built-in tools like Storage Sense or the Uninstall feature instead — they know which files are safe to remove.

What if I delete something and my computer stops working?

If you deleted temporary files or the Recycle Bin contents, restart your computer — usually that fixes it. If you uninstalled a program and something broke, reinstall it. If you deleted a system file and cannot fix it, use a restore point: right-click This PC, select Properties, then System Protection, and click System Restore to go back to an earlier date.

Can I move Windows itself to a different drive?

Not easily. Windows is designed to run from C drive and moving it requires reinstalling the entire operating system on the new drive. If your C drive is too small, your better option is to replace it with a larger drive and reinstall Windows, or add a second drive and move your files there instead.

Will clearing space make my computer faster?

Freeing space will make your computer run more smoothly if C drive was nearly full, because Windows needs free space to create temporary files and run updates. Once you have 15 percent free, additional space has little effect on speed. If your computer is still slow, the problem is usually something else — a full hard drive is one cause among many.

This guide is for general information only and is not medical, financial, legal, or other professional advice. For decisions specific to your situation, consult a qualified professional. See our Editorial Policy.