Quick Answer
To run Disk Cleanup on Windows 10: press Win+R, type cleanmgr, press Enter, select your drive (usually C:), click OK. Check all boxes including Temporary files, Recycle Bin, Thumbnails, and System error dumps. For system files: click "Clean up system files" in the same window — this unlocks Windows Update Cleanup which can free 5–20 GB. Total time: 2–5 minutes.
Your C: drive is getting full, Windows is warning you about low disk space, or your PC has simply slowed to a crawl. Before you buy a bigger hard drive or panic-delete random files, there is a faster and safer solution built directly into every copy of Windows 10 and Windows 11: Disk Cleanup.
Disk Cleanup (the tool behind the command cleanmgr) removes junk files that Windows generates automatically and never cleans up on its own — Windows Update packages that have already been applied, old thumbnail caches, error logs, temporary installation files, and more. Most users recover 5 to 20 GB in under five minutes, with no third-party software required.
This guide covers every method available, from the two-minute cleanmgr approach to automated Storage Sense and manual temp folder purges. Follow them in order for maximum results.
7 Methods at a Glance
What Does Disk Cleanup Actually Remove?
Before jumping in, it helps to know exactly what each category in Disk Cleanup removes. This table covers every standard entry you will see, plus typical sizes from a PC that has been in use for 1–3 years without cleanup.
| Category | What It Removes | Typical Size | Safe to Delete? |
|---|---|---|---|
| Windows Update Cleanup | Old update packages already applied; needed only to uninstall those updates | 2–15 GB | Yes (system files scan required) |
| Temporary Internet Files | Browser and system cache files from Internet Explorer / Edge Legacy | 50–500 MB | Yes |
| Delivery Optimization Files | Update files cached to share with other PCs on your network | 1–5 GB | Yes |
| Temporary Files | Files in the system %Temp% folder not modified in over a week | 100 MB–2 GB | Yes |
| Recycle Bin | Files you have already deleted but not permanently removed | Varies | Yes (if you no longer need them) |
| Thumbnails | Preview images for photos, videos, and documents cached by Explorer | 100–800 MB | Yes (regenerated automatically) |
| System Error Memory Dumps | Crash dump files created during Blue Screen of Death events | 100 MB–1 GB | Yes (after confirming issues are resolved) |
| Previous Windows Installation | Windows.old folder left after an OS upgrade (e.g., Win 10 to Win 11) | 5–25 GB | Yes (removes ability to roll back OS) |
| DirectX Shader Cache | Compiled GPU shader files from games and applications | 100–500 MB | Yes (regenerated on next use) |
| Downloaded Program Files | ActiveX controls and Java applets downloaded for web pages | Under 10 MB | Yes |
Run Disk Cleanup via cleanmgr (Win+R)
High ImpactThis is the standard Disk Cleanup run that handles everyday junk: temporary internet files, thumbnails, recycle bin, error dumps, and DirectX shader cache. Takes about two minutes and requires no administrator privileges for the basic scan.
- Press Windows + R to open the Run dialog. Type
cleanmgrand press Enter. - A drive selection window appears. Make sure C: is selected (it usually is by default) and click OK.
- Windows scans your drive for junk files — this takes 20–60 seconds depending on drive speed.
- In the results window, check every box in the list: Temporary Internet Files, Delivery Optimization Files, Thumbnails, Recycle Bin, Temporary Files, System Error Memory Dumps, and DirectX Shader Cache.
- The "Files to delete" total at the bottom of the window updates as you check boxes — this shows how much space you will reclaim.
- Click OK, then click Delete Files when Windows asks for confirmation. The cleanup runs and the window closes automatically when complete.
Clean Up System Files (Unlocks Windows Update Cache)
High ImpactThe standard cleanmgr scan deliberately excludes certain system-level categories to avoid needing administrator rights. Clicking "Clean up system files" re-runs the scan with elevated privileges and reveals the biggest category of all: Windows Update Cleanup, which stores every update package Windows has ever applied in case you want to uninstall them. On a PC that has received years of monthly cumulative updates, this folder can reach 10–20 GB.
- Run
cleanmgras in Method 1 above. After the initial scan results appear, click "Clean up system files" at the bottom left of the Disk Cleanup window. - If prompted by User Account Control, click Yes to allow the elevated scan. Windows runs a second, deeper scan — this may take 1–2 minutes.
- The results window reopens with additional categories. Look for Windows Update Cleanup near the top of the list — this is typically the largest single entry and will show its size in GB, not MB.
- Also check Previous Windows Installation(s) if it appears — this is the Windows.old folder left after a major OS upgrade and can be 8–25 GB on its own.
- Check all boxes including the new system-level categories and click OK → Delete Files. This deletion process may take 5–15 minutes because of the large files being removed.
- Do not interrupt the process. The window will close automatically when finished. A restart may be required.
Use Storage Sense for Automated Cleanup
High ImpactStorage Sense is Windows 10's built-in automation layer for disk cleanup. Once configured, it runs silently in the background on a schedule you define — permanently eliminating the problem of junk accumulation. It also handles OneDrive cloud file management and Recycle Bin auto-emptying, which cleanmgr does not automate.
- Open Settings (Windows + I), then go to System → Storage.
- At the top, toggle Storage Sense to On.
- Click "Configure Storage Sense or run it now" to open the full settings panel.
- Set "Run Storage Sense" to Every month (or "During low free disk space" if you prefer reactive cleanup).
- Under Temporary Files, enable "Delete temporary files that my apps aren't using" and set "Delete files in my recycle bin if they have been there for over" to 30 days.
- Under Locally available cloud content, set OneDrive files to become online-only after 60 days if unused — this frees space without deleting your files from the cloud.
- Scroll to the bottom and click "Clean now" to run Storage Sense immediately for the first time.
Delete the Temp Folder Manually (%temp%)
Medium ImpactThe Disk Cleanup tool only removes temp files that have not been modified in over a week. The %temp% folder often contains additional files from recent sessions — partial downloads, installation files, and application logs — that are safe to delete but are excluded from cleanmgr because of their recent modification dates. Deleting this folder manually catches everything cleanmgr misses.
- Press Windows + R, type
%temp%, and press Enter. File Explorer opens directly in your user Temp folder (typicallyC:\Users\YourName\AppData\Local\Temp). - Press Ctrl + A to select all files and folders in the directory.
- Press Delete (or Shift+Delete to skip the Recycle Bin). Windows will prompt you for files that are currently in use by running programs — click "Skip" on these. Do not force-delete locked files, as this can crash running applications.
- Empty the Recycle Bin if you used the regular Delete key.
- Repeat with the second temp location: press Windows + R, type
temp(without the percent signs), press Enter, and delete all contents there as well. This is the system-wide temp folder atC:\Windows\Temp.
Empty Recycle Bin and Audit Your Downloads Folder
Low ImpactTwo overlooked locations accumulate gigabytes silently: the Recycle Bin (which holds "deleted" files until you empty it) and the Downloads folder (which most users never sort through). Together these can hold 5–30 GB of files you no longer need.
- Right-click the Recycle Bin icon on your Desktop and select "Empty Recycle Bin." Confirm the deletion. If you are not sure about its contents, open it first and review before emptying.
- Open File Explorer and navigate to C:\Users\YourName\Downloads. Sort the files by Date modified (click the column header).
- Select everything older than 3 months that you no longer need — old installers, PDF files you have already read, zip archives you have already extracted, driver files from old hardware. Delete them.
- Pay particular attention to .exe and .msi installer files — these are commonly 200 MB to 2 GB each and serve no purpose once a program has been installed. They are always re-downloadable if you ever need to reinstall.
- Sort by Size (largest first) to quickly find and eliminate the biggest space hogs in the folder.
Uninstall Unused Programs
Medium ImpactPrograms you installed once and never use again occupy disk space, slow startup times with background services, and clutter your system. The Settings app makes it easy to sort by size and identify the biggest candidates for removal.
- Open Settings → Apps → Apps & features (Windows 10) or Settings → Apps → Installed apps (Windows 11).
- Click the Sort by dropdown and choose Size to show the largest programs at the top.
- Scroll through the list and identify anything you have not opened in the past six months: old games, trial software, manufacturer utilities (common on HP, Dell, and Lenovo machines), outdated toolbars, and media players you replaced.
- Click on any program you want to remove and select Uninstall. Follow the uninstall wizard for each program.
- After uninstalling, go to Task Manager → Startup tab and check whether any leftover startup entries remain — some programs leave these behind even after being uninstalled.
Move Files to OneDrive or External Drive
Low ImpactWhen your drive is genuinely full of files you want to keep — photos, videos, project archives — moving them off the local drive is the right solution. Windows 10 and 11 make this seamless with OneDrive's "Files On-Demand" feature, which keeps files accessible without storing them locally.
- For OneDrive: open the OneDrive folder in File Explorer, move your large files and folders into it, then right-click them and select "Free up space." The files remain visible and accessible in File Explorer but are stored in the cloud rather than on your drive.
- For an external drive or USB drive: connect the drive, then use File Explorer to move (not copy) your files to it by selecting them and pressing Ctrl + X, navigating to the external drive, and pressing Ctrl + V.
- Large folders to prioritize moving: personal video recordings, photo libraries going back more than a year, old project archives, and large zip files from completed work.
- After moving files to an external drive, confirm they are all accessible there before deleting the local copies. Never delete originals before verifying the transfer.
- For maximum cloud storage, consider upgrading to Microsoft 365 (includes 1 TB of OneDrive storage per user) if you need to move large amounts of data off your local drive permanently.
One Thing to Never Delete: Windows System Files
Disk Cleanup is safe precisely because it only touches files that Windows has specifically identified as removable. Never manually delete files inside C:\Windows\System32, C:\Windows\SysWOW64, or C:\Program Files unless you know exactly what you are removing. Deleting the wrong system file can prevent Windows from booting. Stick to the methods above and you will not accidentally break anything.
Disk Cleanup on Windows 11: Same Tool, Same Steps
Windows 11 ships with the same cleanmgr utility that has been in Windows since Windows 98. The tool looks identical and the steps above apply without any changes. Press Win+R, type cleanmgr, and follow Methods 1 and 2 exactly as described above.
The main difference in Windows 11 is that Storage Sense (Method 3) is more prominently featured and slightly easier to configure — it appears at the top of Settings → System → Storage with a cleaner interface. The underlying functionality is the same.
Microsoft has announced plans to eventually retire the classic Disk Cleanup tool in favor of Storage Sense, but as of 2026 cleanmgr remains fully functional on both Windows 10 and Windows 11.
After Cleanup: How to Maintain a Clean Drive Long-Term
Enable Storage Sense (Method 3) to run automatically every month. Set your browser to clear its cache on exit. Avoid installing software you plan to use once and then forget about. Keep at least 10–15% of your C: drive free at all times — Windows needs that headroom to create page files and temporary working space. These four habits prevent 90% of low-disk-space problems before they start.
PC Still Slow After Cleanup?
Freeing disk space improves performance when a full drive was the bottleneck, but slowness often has other causes: too many startup programs, malware running in the background, outdated drivers, or aging hardware that has reached its limits.
If your PC is still sluggish after completing all the methods above, the next diagnostic step is to open Task Manager (Ctrl + Shift + Esc) and check the CPU, Memory, and Disk columns. Any column pinned near 100% points to a different problem that needs a different fix.
At IT Cares, our remote technicians handle the full diagnostic workflow for you — identifying whether your slowdown is caused by software, malware, failing hardware, or simply a configuration that needs optimization. Most sessions are completed in under 60 minutes, and you never need to leave your home or office.
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