Open Settings > System > Storage. Windows breaks your drive down by category (Apps, Temporary files, Documents, Pictures, and more) and shows how many gigabytes each one uses. This is the fastest native way to see what is using disk space on Windows 11 and Windows 10, with no downloads required.

TL;DR

  • Go to Settings > System > Storage for a per-category breakdown of your C: drive.
  • Click Show more categories to expand the full list past the top few.
  • Turn on Storage Sense to auto-clean temp files and old downloads on a schedule.
  • Use Storage > Temporary files to safely delete caches, Recycle Bin, and Windows Update leftovers.
  • For the single biggest folders, sort by size in File Explorer or use the disk cleanup categories.

Where do I see the storage breakdown on Windows 11?

Go to Settings > System > Storage (on Windows 10 it is Settings > System > Storage as well, with a slightly different layout). At the top you get a bar chart of your system drive split into categories. Click Show more categories to reveal everything, including System & reserved, Other, and Maps.

Each category is clickable. Selecting Apps & features lists installed programs sorted by size, and Temporary files itemizes what is safe to remove.

How do I clean temporary files safely?

Go to Settings > System > Storage > Temporary files. Windows pre-selects the genuinely safe items: Temporary Internet Files, Recycle Bin, Thumbnails, and Windows Update Cleanup. Review the checkboxes, then click Remove files.

Leave Downloads unchecked unless you have reviewed that folder, because it deletes files you may still want. Windows Update Cleanup can reclaim several gigabytes after a feature update, since it removes the old rollback copy.

What is Storage Sense and how do I turn it on?

Storage Sense is the built-in automatic cleaner. Go to Settings > System > Storage and toggle Storage Sense on, then click it to open its schedule. You can set it to run When free disk space is low, Every day, Every week, or Every month, and choose how long to keep files in the Recycle Bin and the Downloads folder before they are deleted.

It also handles cloud-backed content: if you use OneDrive, Storage Sense can make synced files online-only after a set period. That ties into why OneDrive takes up local hard drive space in the first place.

How do I find the biggest folders without third-party tools?

Windows Storage settings group by category, not by folder, so for the largest individual folders open File Explorer, navigate into a drive or folder, and switch to Details view. Right-click a column header, choose More, and add the Size column, then click it to sort. File Explorer does not roll up folder sizes automatically, so this works best inside a single folder of files.

For a true folder-by-folder map, our guide on finding the largest files on Windows 11 without third-party apps covers PowerShell one-liners that rank files by size across an entire directory tree.

What the OS does natively, and where it stops

Windows natively gives you accurate per-category totals, a safe temp-file cleaner, and scheduled automatic cleanup through Storage Sense. That covers most everyday "my disk is full" situations.

Where it stops: Windows will not draw you a visual treemap, and it will not show you which deeply nested folders are the heaviest. For that level of detail you need a dedicated scanner like the one covered in what TreeSize Free is and how to use it.

What this cannot do / leave alone

Do not manually delete files from C:\Windows, C:\Windows\System32, or the hidden WinSxS component store. WinSxS looks huge in some scanners but is managed by Windows itself; remove things from it only through Dism /Online /Cleanup-Image /StartComponentCleanup, never by hand. Also leave System Restore and pagefile.sys alone unless you understand the tradeoffs, since both serve recovery and performance.

FAQ

Why does my C: drive fill up even after deleting files?

Deleted files sit in the Recycle Bin until it is emptied, and Windows Update keeps rollback copies. Clear both via Settings > System > Storage > Temporary files, and check whether a synced cloud folder is keeping local copies.

Is Storage Sense safe to leave on?

Yes. By default it only removes temporary files and items already in the Recycle Bin past your chosen age. Just review the Downloads retention setting so it does not delete files you meant to keep.

Why does Storage settings show a large "Other" or "System & reserved" category?

"System & reserved" includes the pagefile, hibernation file, and system restore points, which are normal. "Other" is files that do not fit a named category, often large game or application data folders; use File Explorer to locate them.

If the device that is really out of space is your iPhone, Cleanor for iPhone finds the photos and clutter eating that storage too.