Windows built-in storage tools show you exactly which files and folders are taking up the most room

Your PC's storage fills up gradually, and by the time you notice, you may have gigabytes locked away in places you forgot about. Windows includes two straightforward tools to find what's consuming space: Storage Sense and the Disk Usage Analyzer. Both are free and built into your system—you don't need to read anything.

Storage Sense gives you a quick overview of what's eating space by category (apps, photos, videos, temporary files). The Disk Usage Analyzer shows you a visual breakdown of individual folders so you can drill down to the exact culprit. Most people find what they're looking for in under five minutes using one of these two.

Key Takeaways

  • Open Settings, go to System > Storage, and turn on Storage Sense to see a breakdown by file type and get recommendations for what to delete.
  • Use the Disk Usage Analyzer (built into Windows 10 and 11) to see which folders are largest and navigate directly to them for manual cleanup.
  • Large folders are often Downloads, AppData, Program Files, or old backup files—check these first if you're in a hurry.
  • Temporary files, old Windows installations, and duplicate photos accumulate silently and often account for 10 to 50 gigabytes of wasted space.
  • If a folder shows as large but you can't see its contents, it may contain hidden system files—enable "Show hidden files" in View options to investigate.

Using Storage Sense for a quick overview

Storage Sense is the fastest way to see what's taking up space without opening folders. Open Settings by pressing Windows key + I, then navigate to System in the left sidebar and select Storage. You'll see a bar showing how much space is used and how much is free, with a breakdown by category: Apps & games, Photos, Videos, Music, Documents, and Other.

Click on any category to see what's inside it. If you click Videos, for example, you'll see a list of your largest video files. You can delete files directly from this view by right-clicking and selecting Delete. Storage Sense also shows Temporary files as a separate category—these are safe to delete and often free up several gigabytes.

At the bottom of the Storage page, you'll see a toggle for Storage Sense. Turn it on and set it to run automatically (weekly, monthly, or when space runs low). Storage Sense will then delete temporary files and empty your Recycle Bin on a schedule, so you don't have to think about it.

Using Disk Usage Analyzer to find large folders

If Storage Sense doesn't pinpoint the problem, use the Disk Usage Analyzer to see which folders are largest. Press Windows key + S to open search, type Disk Usage, and select the app that appears. It will scan your entire drive and show you a tree view of folders ranked by size.

The largest folders appear at the top. Click the arrow next to any folder to expand it and see what's inside. If you see a folder taking up 20 gigabytes, you can expand it to see whether it's full of videos, old installers, or something else. Once you've found the culprit, you can right-click the folder in the analyzer and select Open in File Explorer to navigate there and delete files manually.

The Disk Usage Analyzer scans slowly on first run (it may take a few minutes on a large drive), but once it finishes, you can click Refresh to update the results after you've deleted files.

Common places where storage gets hidden

Downloads folder: Most people accumulate installers, PDFs, and old files here without realizing it. Open File Explorer, click Downloads in the sidebar, sort by size (right-click the column header and select Size), and delete anything you no longer need.

AppData folder: This hidden folder stores settings and temporary data for your programs. To see it, open File Explorer, click View at the top, and check Hidden items. Navigate to C:\Users\[Your Username]\AppData. The Local subfolder often contains cache files from browsers and apps—these are usually safe to delete, but do not delete anything in the Roaming subfolder, as it contains important program settings.

Program Files: Some applications install large files here and don't clean them up when uninstalled. Open C:\Program Files and C:\Program Files (x86) to see what's installed. If you see folders for programs you no longer use, uninstall them through Settings > Apps > Installed apps rather than deleting the folders manually.

Windows.old folder: If you recently updated Windows, a folder called Windows.old may exist on your drive. This is a backup of your previous Windows installation and can be 20 to 30 gigabytes. You can safely delete it after confirming your system is working correctly. Right-click it and select Delete, or use Disk Cleanup (see below).

Using Disk Cleanup for automatic removal

Disk Cleanup is a built-in Windows tool that removes temporary files, old Windows installations, and other safe-to-delete items automatically. Press Windows key + S, type Disk Cleanup, and select the app. Choose the drive you want to clean (usually C:) and click OK.

Disk Cleanup will scan and show you categories of files it can remove: Temporary Internet Files, Recycle Bin, Temporary files, and others. Check the boxes next to the categories you want to delete, then click Clean up system files at the bottom. This will also show you the Windows.old folder if it exists. Click OK to delete the selected items.

Disk Cleanup is safer than manually deleting folders because it only targets files Windows knows are temporary or redundant. If you're unsure whether something should be deleted, leave that checkbox unchecked.

Checking for duplicate files and old backups

Duplicate photos and old backup files often hide in plain sight. Open File Explorer and navigate to your Pictures folder. If you've synced photos from a phone or camera multiple times, you may have dozens of identical images. Sort by date and look for clusters of photos taken on the same day—these are often duplicates.

Check your Documents folder for old backup copies of files (often named with a date or "backup" in the filename). These are safe to delete if you have a current version. Also check your Desktop for old installers or files you've forgotten about.

If you use cloud storage (OneDrive, Google Drive, Dropbox), check whether your entire cloud folder is synced to your PC. Open File Explorer, right-click your cloud folder, and select Properties. If the size is larger than expected, you may be storing files locally that you only need in the cloud. You can change sync settings to store files online only, which frees up local space while keeping them accessible.

What to do if you can't delete a file

If you find a large file or folder but can't delete it, it's usually because Windows or another program is using it. Close all open programs and try again. If the file is still locked, restart your PC and try deleting it when ready after startup, before programs have time to load.

If a folder appears large but you can't see its contents, it may contain system files. Do not force-delete system folders (anything in Windows, System32, or ProgramData). These are essential to your PC's operation. If you suspect a system folder is taking up unusual space, take a screenshot of the Disk Usage Analyzer and contact a local computer repair shop—they can investigate safely.

Frequently Asked Questions

How much storage space should I keep free on my PC?

Windows performs best when at least 10 to 15 percent of your drive is free. If your drive is more than 90 percent full, your PC will slow down noticeably. Use the Storage tool in Settings to check your current usage and aim to keep at least 50 to 100 gigabytes free if your drive is 500 gigabytes or larger.

Is it safe to delete everything in the Temp folder?

Yes, the Temp folder (usually C:\Users\[Your Username]\AppData\Local\Temp) contains temporary files that programs create and discard. Deleting everything in it is safe and often frees up several gigabytes. If a program is actively using a temp file, Windows will prevent you from deleting it, so you won't accidentally break anything.

Why does my drive show as full when Storage Sense says I have free space?

This usually means hidden system files are taking up space. Open File Explorer, click View, and check Hidden items to see them. System files in AppData and ProgramData folders are often large but invisible by default. Do not delete these—they're essential to Windows and your programs.

Can I move files to an external drive to free up space?

Yes, and it's often the best solution for large photo or video libraries. Connect an external drive, open File Explorer, and drag folders (like Pictures or Videos) to the external drive. Once the transfer finishes, you can delete the originals from your PC. Just keep the external drive plugged in or backed up elsewhere so you don't lose the files.

What if the Disk Usage Analyzer shows space used but I can't find the files?

Enable hidden files (View > Hidden items in File Explorer) and check the AppData and ProgramData folders. If a folder still shows as large but appears empty, it may contain system files or files in use by Windows. Do not force-delete these. If you're concerned about space, restart your PC and run the analyzer again—sometimes files locked by running programs show as taking space but are actually temporary.