Quick fix: Disk Cleanup (cleanmgr) misses many recoverable categories. For complete cleanup, run Disk Cleanup as admin (System Files button) plus DISM /Online /Cleanup-Image /StartComponentCleanup /ResetBase for WinSxS, plus powercfg /h /size 50 for hibernation file. Together these recover the GBs Disk Cleanup leaves behind.

You run Disk Cleanup, tick every box, and it claims to free 5 GB. After completion, free space increased by only 1 GB. Or worse: WizTree shows 15 GB still in temp/cache folders that Disk Cleanup missed. The tool has known blind spots — folders it doesn’t touch even with all options selected, deeper system caches that require separate commands.

Symptom: Disk Cleanup runs but recovered space is much less than expected; large cache folders remain unaddressed.
Affects: Windows 11 (and Windows 10) Disk Cleanup tool.
Fix time: ~30 minutes for full cleanup.

What causes this

Disk Cleanup’s default mode operates only on per-user files (browser cache, Recycle Bin, etc.). It doesn’t touch system-level cleanup unless run with admin elevation via the “Clean up system files” button. Even with admin elevation, several categories are unreachable: the per-app caches under %LocalAppData% (browsers, Slack, Discord, Spotify), the OneDrive cache, the WSL2 VHDX file, the hibernate file at the size Windows chose, and many app-specific temp folders.

The fix is to use Disk Cleanup’s admin mode for what it handles, then chain additional commands for what it doesn’t.

Method 1: Run Disk Cleanup with admin elevation

The basic step many users miss.

Press Win + R, type cleanmgr, press Enter.
Pick the C: drive. Click OK.
The first screen shows user-level cleanups only. Click Clean up system files (button at the bottom-left). This requires admin elevation.
After elevation, the dialog re-opens with additional categories visible: Windows Update Cleanup, Delivery Optimization Files, Device driver packages, Previous Windows installation(s), System error memory dump files, Windows ESD installation files, Windows upgrade log files.
Tick every category. The big-ticket items are:
- Previous Windows installation(s) — can be 10–25 GB after a feature update. Removes the Windows.old folder.
- Windows Update Cleanup — 2–6 GB.
- Delivery Optimization Files — 0.5–3 GB.
- Windows ESD installation files — ~3 GB if present.
Click OK → Delete Files. The cleanup runs for 5–30 minutes.
Reboot. Some categories don’t fully free space until next reboot finalizes the operations.

This alone recovers most of the cleanup the tool can do.

Method 2: Run cleanup commands Disk Cleanup doesn’t expose

For categories Disk Cleanup ignores.

Open Terminal (Admin).
Clean the WinSxS component store:
```
DISM /Online /Cleanup-Image /StartComponentCleanup
DISM /Online /Cleanup-Image /StartComponentCleanup /ResetBase
```
The /ResetBase flag is more aggressive — you can no longer uninstall previously-installed updates after this. Use only on stable installs.
Reduce the hibernation file (if you don’t use hibernate):
```
powercfg /h /size 50
```
Sets hibernate file to 50% of RAM size. To disable entirely: powercfg /h off (saves ~RAM-sized GB).
Reduce shadow copy storage:
```
vssadmin list shadowstorage
vssadmin resize shadowstorage /For=C: /On=C: /MaxSize=5GB
```
Caps System Restore allocation at 5 GB. Old restore points are dropped.
Clear app caches: browse to %LocalAppData% and look for large folders. Common offenders:
- Microsoft\Edge\User Data\Default\Service Worker
- Google\Chrome\User Data\Default\Service Worker
- Discord\Cache
- Slack\Cache
- Spotify\Storage
Right-click each, Properties to check size. Delete contents (not the folder itself) for those over 500 MB.
Clear Windows temp directly:
```
del /f /s /q %TEMP%\*
del /f /s /q C:\Windows\Temp\*
```
Some files won’t delete (in use); ignore those errors.

This typically recovers an additional 5–15 GB beyond Disk Cleanup.

Method 3: Use third-party tools for deep cleanup

For when Methods 1 and 2 leave you still short on space.

Download WizTree from diskanalyzer.com. Free, reads NTFS MFT directly for near-instant scanning.
Run WizTree, scan C:. Within 30 seconds, see every folder sorted by size.
Identify candidates for deletion that Disk Cleanup missed:
- WSL2 VHDX files (Linux distros): typically in %LocalAppData%\Packages\CanonicalGroupLimited.*\LocalState\ext4.vhdx — can be 10+ GB if you ran heavy Linux workloads. Use wsl --shutdown, then compact with Optimize-VHD from PowerShell.
- Docker volumes: C:\ProgramData\Docker\windowsfilter if Docker Desktop is installed. Use docker system prune -a to clean.
- Old game files: Steam library, Origin, Epic Games. Move or delete games you don’t play.
- OneDrive cache: if you have very large OneDrive content, the offline cache can be massive. Right-click files/folders in OneDrive → Free up space to revert to cloud-only without deleting.
Use BleachBit (free, opensource) for safe automated cleaning of app caches Disk Cleanup misses. Run in Preview mode first to see what it’ll do.
Use TreeSize Free as an alternative to WizTree if you prefer hierarchical view.
Avoid “PC cleaner” ads — they typically inflate findings and bundle unrelated software. Stick with WizTree, BleachBit, or TreeSize.

This is the right path for deep cleanup on devices with persistent space issues.

How to verify the fix worked

Open Settings → System → Storage. Free space at top should increase by what you cleaned.
Run Get-Volume C | Format-List Size, SizeRemaining in PowerShell for exact bytes.
Use WizTree to compare folder sizes before/after each cleanup step — quantifies what each step actually recovered.

If none of these work

If you’re still short on space after deep cleanup, the data is just too large for the drive. Move user folders to another drive: right-click Documents (or Pictures, Videos, etc.) → Properties → Location tab → Move. Pick a folder on a different drive. Windows moves files and updates references. Move app data: some apps (Steam, Visual Studio installs) support relocating to other drives via their own settings. Sparse files: NTFS supports sparse files (files with zero bytes that take less space). Run fsutil sparse setflag <path> on large files with lots of zeros for theoretical savings, but practical benefit is limited. NTFS compression: right-click folder → Properties → Advanced → Compress contents to save disk space. Saves 20–50% on text files, less on binary. Last resort: upgrade the drive. SSD prices: ~$60 for 500 GB, ~$110 for 1 TB. Often cheaper than spending hours hunting for space to recover.

Bottom line: Disk Cleanup’s admin mode + DISM /StartComponentCleanup + powercfg /h reduction + manual cache cleanup recover the GBs that the default tool misses. WizTree shows you what’s actually big.