To free up space on a full C drive, open Settings, then System, then Storage, and see what is using it. Turn on Storage Sense, clear temporary files and the Recycle Bin, empty Downloads, uninstall programs you do not use and move photos and videos to an external drive or cloud storage. Do not delete Windows or Program Files folders by hand. If the drive is still full after that, the drive is simply too small, and a larger SSD is the lasting fix.
A nearly full C drive makes a laptop slow, stops Windows updates installing and makes programs crash or refuse to save. The cure is rarely a clever tool. It is finding the few large things that take most of the space and deciding what to keep. This guide shows how to see where the space has gone, which clean-up steps are safe, which ones to leave alone and when a bigger drive is the honest answer.
Step 1: see what is using the space
Open Settings, then System, then Storage. Windows shows a bar split into categories such as Apps and features, Temporary files, Documents, Pictures, Videos and System and reserved. Click Show more categories for the full list. The top two or three categories usually account for most of the drive. Photos and videos, downloads and installed programs are the common culprits. For a deeper look at big files, search for the largest ones: open File Explorer, click This PC, and in the search box type size:gigantic, which lists files over 128 MB.
Step 2: the safe clean-up
- Temporary files. In Storage, open Temporary files, tick Temporary files, Windows Update Cleanup and the Recycle Bin, and remove them. Leave Downloads unticked until you have looked at it yourself.
- Storage Sense. Turn it on in Storage. It clears temporary files and old Recycle Bin items on a schedule.
- Downloads folder. Sort it by size and delete installers and files you no longer need. This folder often holds several gigabytes.
- Uninstall unused programs. In Settings, Apps, Installed apps, sort by size, and remove what you do not use. Games and design software are large.
- Move big personal files. Copy photos and videos to an external drive, check that they open there, and then delete them from the laptop. Copy first and delete afterwards.
- Use cloud storage with care. OneDrive's Files On-Demand keeps files online and removes the local copy, so it saves space if you have the cloud storage to hold them. Right-click a folder and choose Free up space.
Step 3: the larger Windows items
- Previous Windows installation. After a major update, Windows keeps the old version for a limited time so you can go back. It can take many gigabytes. Remove it from Temporary files in Storage, or from Disk Cleanup, only when you are sure you will not go back.
- Hibernation file. The hiberfil.sys file is about as large as part of your RAM. If you never use hibernate, you can turn it off with the command powercfg /h off in an administrator Command Prompt. This also disables Fast Startup. Turn it back on with powercfg /h on.
- System Restore. Restore points take space. In System Protection settings you can reduce the share they may use, but do not turn it off if it is your safety net.
- Component store. The WinSxS folder looks huge, but it holds shared files, and many are links. Never delete it by hand. If you must clean it, use the command DISM /Online /Cleanup-Image /StartComponentCleanup.
What not to do
- Do not delete files from the Windows, Program Files or ProgramData folders by hand. You can break Windows or programs.
- Do not use "registry cleaners" or "PC optimiser" programs. They free little space and can cause harm.
- Do not delete a file just because you do not recognise it. Search for its name first.
- Do not clean up with only one copy of precious files. Back up before you delete. See laptop data backup.
How much free space should you keep?
As a rule of thumb, aim for at least 15 to 20 percent of the drive free, and more on a small drive. Windows needs room for updates, the page file and temporary work. A 256 GB drive with only a few gigabytes free will struggle whatever else you do.
If the drive is simply too small
Some laptops, especially older or budget ones, ship with a small drive that fills up after a few years of updates. When clean-up gives only a short respite, you have three real options:
- Add an external drive for photos, videos and downloads.
- Replace the drive with a larger SSD. This fixes space, and an SSD also speeds up a laptop that still has a hard disk. Our guide on cloning to a new SSD or doing a fresh install explains how the move works, and SSD vs HDD compares the two.
- Resize partitions if the drive has unused space in another partition. Disk Management can extend C: only into unallocated space right next to it, so this is not always possible.
If the laptop is slow for other reasons too, our laptop running slow guide covers the rest.
When to ask for help
Ask for help if the drive fills up again after clean-up, if storage shows hundreds of gigabytes under "System and reserved", or if updates fail with a space error even after you free space. A hidden problem such as a runaway log, a corrupt update cache or malware is possible. Our laptop SSD upgrade and laptop performance optimization pages explain what we do. Call or WhatsApp to book, and see laptop repair near me for the nearest branch.
Frequently asked questions
Why is my C drive full when I have not saved much?
Windows updates, the previous Windows installation, the hibernation file, system restore points, app caches and temporary files can take many gigabytes. Storage settings show the split.
Is it safe to delete the Windows.old folder?
Yes, through Settings or Disk Cleanup, once you are sure you do not want to go back to the previous version. Do not delete it by hand.
Will deleting files make my laptop faster?
Only if the drive was nearly full. A drive with enough free space does not get faster because you delete more.
Can I move programs to another drive?
Some apps allow it from Settings, Apps. Many programs must be uninstalled and installed again on the other drive.
