The drive is full and warnings keep appearing
My C drive is full but I do not know what is using the space.
Written by The CommonFixes team · fact checked by CommonFixes review desk
Last updated
Short answer
Temporary files, old update copies and hibernation files quietly consume tens of gigabytes without ever appearing in your folders. The quickest thing to try first: see what is actually there — Open Settings, System, Storage. It breaks the drive down by category so you can see whether apps, videos or temporary files are to blame. Most people are done in about 20 minutes.
Full walkthrough below: 5 steps for Windows and Mac, rated easy.
Sounds like this
- •Red bar on the drive
- •Low disk space warning
- •Cannot save or update
Why it happens
Temporary files, old update copies and hibernation files quietly consume tens of gigabytes without ever appearing in your folders.
Work through these in order
0% done- 1
See what is actually there
Open Settings, System, Storage. It breaks the drive down by category so you can see whether apps, videos or temporary files are to blame.
- 2
Clear temporary and old update files
In Storage, open Temporary files and tick Windows Update Cleanup and Previous Windows installations. These alone often free twenty gigabytes or more.
- 3
Turn on Storage Sense
In the same screen, switch on Storage Sense so Windows empties the recycle bin and clears temporary files automatically.
- 4
Move large folders elsewhere
Sort your Downloads and Videos folders by size and move the biggest items to an external drive or cloud storage.
- 5
Turn off hibernation if you never use it
Open Terminal as administrator and run powercfg /hibernate off. This releases several gigabytes on most machines.
If none of that worked
Install WizTree or TreeSize Free. They map every folder by size in seconds and reveal the hidden giant.
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Who wrote this and how we checked it
The CommonFixes team
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We are a small group of people who spend our days repairing laptops and desktops for family, friends and small offices. Every guide here starts with a problem someone actually brought to us, and we only write down the steps that put the machine right.
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CommonFixes review desk
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This guide was last updated on 10 August 2026. If a step no longer matches what you see on screen, tell us on the contact page and we will test it again.
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