File Explorer has a built-in Size search filter that works on any folder and can scan the whole C: drive. No TreeSize install required.

Short answer: open File Explorer, navigate to This PC > C:, click the search box, type size:gigantic (files > 128 MB), press Enter. Sort by Size to find the biggest files on the drive.

Using File Explorer search filters

File Explorer's search box accepts a size: keyword with named ranges or numeric thresholds.

Named ranges:

  • size:tiny — 0 to 10 KB
  • size:small — 10 to 100 KB
  • size:medium — 100 KB to 1 MB
  • size:large — 1 to 16 MB
  • size:huge — 16 to 128 MB
  • size:gigantic — over 128 MB

Numeric thresholds:

  • size:>1GB
  • size:>500MB
  • size:>100MB AND <1GB

Finding the biggest files on C:

  1. open File Explorer
  2. navigate to This PC > C:
  3. click inside the Search box (top right)
  4. type size:>1GB and press Enter
  5. wait — the first scan takes several minutes (indexing status shows in the address bar)
  6. click the Size column header to sort largest-first
  7. right-click a result > Open file location to see where it lives before deciding what to do

Expect hibernation files, page files, game installs, VM disk images, and old backups to dominate. Note paths before deleting — a 10 GB hiberfil.sys in C:\ is normal system state; a 10 GB .vhdx in a forgotten folder probably is not.

Filtering by file type

Combine filters for targeted searches:

  • size:>500MB ext:.mp4 — big video files
  • size:>200MB ext:.zip OR ext:.7z — big archives
  • size:>1GB ext:.iso OR ext:.vhdx OR ext:.vhd — disk images

Better next routes

For a proper visual analyzer, continue with What is TreeSize Free and How to Use It?.

For the broader cleanup, read How to Free Up Space on C Drive Windows 11 Natively.