Your C: drive is nearly full and Windows is warning you about low disk space, but you cannot figure out what is taking up all the room. Large files — old downloads, forgotten backups, installer files, video exports — tend to accumulate invisibly until suddenly there is nowhere left to put anything. Here is how to find and clear them out.
Check What Is Using Your Storage
Windows 11 has a built-in storage breakdown that shows what is taking up space:
- Press Windows + I to open Settings
- Go to System > Storage
- Click on your main drive (usually C:)
You will see a breakdown by category — Apps, Temporary Files, Documents, Videos, etc. Click each category to see more detail and remove items directly from this view.
Run Storage Sense
Storage Sense automatically cleans up temporary files, the Recycle Bin, and old Windows installation files:
- In Settings > System > Storage, click Storage Sense
- Click Run Storage Sense now
Storage Sense can also be configured to run automatically on a schedule and to delete files in the Downloads folder that have not been opened for a set number of days.
Find Large Files Using File Explorer
To search for large files anywhere on your drive:
- Open File Explorer
- Click in the search box in the top right
- Type size:gigantic and press Enter
This shows all files over 128MB. You can also use size:huge (16MB–128MB) or size:large (1MB–16MB). Review the results and delete anything you no longer need.
Check Your Downloads Folder
The Downloads folder is one of the most common sources of wasted space. People download installer files, PDFs, images, and ZIP archives and never clear them out. Navigate to C:/Users/[YourName]\Downloads, sort by size, and delete anything you no longer need.
Clear the Recycle Bin
Files you delete in Windows go to the Recycle Bin and continue to take up space until you empty it. Right-click the Recycle Bin on your desktop and select Empty Recycle Bin.
Delete Old Windows Update Files
Windows keeps old update files that can take up several gigabytes:
- Press Windows + R, type cleanmgr, and press Enter
- Select your C: drive
- Click Clean up system files
- Tick Windows Update Cleanup and any other items you want to remove
- Click OK
Use a Free Tool: WinDirStat or TreeSize Free
For a visual map of what is using space, free tools like WinDirStat or TreeSize Free are excellent:
- WinDirStat — shows a colour-coded block diagram of your entire drive. The biggest blocks are the largest files. Click any block to see the file path.
- TreeSize Free — shows a tree view sorted by size, making it easy to drill into folders and find where space has gone.
Both are free downloads. They make it immediately obvious if you have a single folder eating hundreds of gigabytes.
What to Delete (and What Not To)
Safe to delete:
- Downloaded installer files (.exe, .msi) for software you have already installed
- Old ZIP or RAR archives you have already extracted
- Duplicate photos and videos
- Old project files, documents, and exports you no longer need
Be careful with: anything in Windows system folders (C:/Windows), programme files, or anything you do not recognise — if in doubt, leave it alone.
