You can deep clean Windows 11 or Windows 10 and recover 20GB to 50GB of space using only Microsoft's built-in tools, no third-party cleaner required. The three tools that do the heavy lifting are Storage Sense, Disk Cleanup (for the leftover Windows.old folder), and a File Explorer search trick that surfaces your biggest hidden files.

  • Storage Sense (Settings › System › Storage) automatically clears temp files, caches, and the Recycle Bin on a schedule.
  • Disk Cleanup safely removes Windows.old, often 20-30GB after a major update.
  • The File Explorer search size:>1GB instantly lists every file over 1GB hiding on your drive.
  • Everything here is native to Windows, reversible where it matters, and free.

Why avoid third-party Windows cleaners?

Third-party Windows cleaners are downloadable utilities that promise one-click optimization, but many are unnecessary and some are actively risky. The genuine wins they advertise, clearing temp files, emptying the Recycle Bin, removing update leftovers, are all built into Windows 11 and 10. The downside of the sketchy ones is real: bundled adware, aggressive "registry cleaning" that can break apps, and permissions far beyond what cleaning needs. Microsoft's native tools do the same job without the risk, which is why they're the right starting point for any deep clean.

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

Storage Sense is a built-in Windows utility that monitors your drive and automatically deletes temporary system files, app caches, and old Recycle Bin contents in the background. Set it up once and it keeps your PC tidy without manual effort.

Configure Storage Sense in Windows 11/10:

  1. Press Windows Key + I to open Settings.
  2. Go to Settings › System › Storage.
  3. Toggle Storage Sense to On.
  4. Click the arrow next to Storage Sense to open its settings.
  5. Set Run Storage Sense to Every week or When free disk space is low.
  6. Set Recycle Bin and Downloads cleanup to 30 days (only enable Downloads cleanup if you don't keep files there long-term).
  7. Click Run Storage Sense now at the bottom for an immediate clean.

This safely clears app caches, system error memory dumps, and temporary installation files, the same junk third-party apps charge you to find.

How do I safely delete the Windows.old folder?

Windows.old is a complete backup of your previous operating system, created automatically when you upgrade from Windows 10 to 11 or install a major feature update. It often occupies 20GB to 30GB and you cannot simply drag it to the Recycle Bin, it holds protected system files.

Remove it with Disk Cleanup:

  1. Click Start, type Disk Cleanup, and press Enter.
  2. Select your main drive (usually C:) and click OK.
  3. Click Clean up system files (requires administrator privileges).
  4. Select the C: drive again.
  5. Check the box next to Previous Windows installation(s).
  6. Click OK, then Delete Files to confirm.

The process takes a few minutes and permanently reclaims a large chunk of your drive.

How do I find the largest hidden files on my PC?

Even after Storage Sense runs, gigabytes can still be tied up in forgotten files, old video exports, ISO images, uncompressed archives, buried in your user folders. Instead of clicking through every directory, use the File Explorer search trick:

  1. Open File Explorer (Windows Key + E).
  2. Click This PC in the left sidebar to search everything, or pick your C: drive.
  3. Click the Search box in the top-right corner.
  4. Type exactly size:>1GB and press Enter.

File Explorer lists every file larger than 1GB on the drive. To catch medium files, search size:>500MB. Sort results by size, then right-click anything you don't recognize and choose Open file location to see where it lives before you delete it. This built-in command is faster and safer than any "space sniffer" utility, and it's covered in more depth in our guides on finding the biggest space-wasters and how TreeSize Free works if you ever want a visual map.

Is deep cleaning Windows this way safe?

Yes. Storage Sense and Disk Cleanup only target files Windows itself classifies as safe to remove, temp files, caches, error dumps, and superseded update files. Deleting Windows.old is permanent and means you can no longer roll back to your previous Windows version, so do it only once your current install is stable (after about 10 days Windows deletes it automatically anyway). The File Explorer search doesn't delete anything; it only shows you files so you can decide. Avoid deleting files you don't recognize inside C:\Windows or Program Files without checking what they are first.

More built-in PC cleanup wins

Once the big three are done, a few more native moves free serious space:

Target Where to clean Typical space freed
Old Windows update files Disk Cleanup › Clean up system files 5-30 GB
Hibernation file (hiberfil.sys) Disable hibernation 4-16 GB
Delivery Optimization cache Clear Delivery Optimization files 1-10 GB
Leftover printer/app software Remove old drivers and leftovers varies
Heavy installed games Uninstall PC games properly 20-150 GB

For a broader walkthrough, see our overview of decluttering the AppData folder and whether it's safe to compress the C: drive.

FAQ

Do I need a third-party app to deep clean Windows 11?

No. Storage Sense, Disk Cleanup, and File Explorer's size:>1GB search cover the same ground as most paid cleaners, without ads or risky registry edits.

How much space can I free with built-in Windows tools?

Most users recover 20GB to 50GB, with the biggest single win usually being the Windows.old folder (20-30GB) after a major update.

Is it safe to delete the Windows.old folder?

Yes, but it's permanent. Once deleted you can't roll back to your previous Windows version, so remove it only after confirming your current install runs well.

Will Storage Sense delete my personal files?

No. By default Storage Sense only removes temp files, caches, and Recycle Bin items. Downloads cleanup is opt-in and follows a 30-day rule you set yourself.

What does the size:>1GB File Explorer search do?

It instantly lists every file larger than 1GB on the selected drive so you can review and remove oversized clutter. It only displays files, it never deletes them.

Windows has strong built-in tools, but phones don't, they hide clutter behind opaque "System Data" and offer no size:>1GB search. If your iPhone or Android is also full, Cleanor's phone storage cleanup finds duplicates, large videos, and hidden caches locally, and you can grab the Cleanor iOS app to do it in a few taps.