Best Free Disk Cleanup Tools for Windows That Actually Work

Your C drive is nearly full and Windows is starting to complain. Before you buy a bigger drive or fall for a flashy “one-click PC cleaner,” know this: Windows already includes tools that clear most of the junk for free, and the few third-party apps worth adding are open source and completely free too.

Most disk bloat comes from a handful of predictable places: leftover Windows Update files that can run to many gigabytes, temporary files, the hibernation file, old restore points and app caches. The tools below target exactly those, starting with the ones already on your PC. Work through them in order and you will usually free up plenty without installing anything.

Below are the tools in order, from the easiest built-in option to the most thorough. Most people get all the space they need from the first two.

Method 1: Turn on Storage Sense

Storage Sense is the modern, automatic cleaner built into Windows 10 and 11. Once on, it clears temporary files, empties the Recycle Bin and removes old downloads on a schedule, so you rarely have to think about disk space again.

Open Settings → System → Storage and turn on Storage Sense. Click it to set how often it runs and whether it should delete files in your Downloads folder after a set time. For a one-off clean right now, scroll down and click Cleanup recommendations, which surfaces large temporary files, unused apps and old Windows Update files you can remove in a couple of clicks.

Storage Sense handles the routine junk automatically, but it deliberately leaves some bigger items alone, like old Windows Update files and system caches. For those, the classic Disk Cleanup tool in Method 2 still does more.

Method 2: Run the classic Disk Cleanup tool

The old Disk Cleanup utility (cleanmgr) is still in Windows and still clears things Storage Sense skips, especially Windows Update leftovers, which are often the single biggest space hog after a major update.

Press Win + R, type cleanmgr and press Enter. Pick your C drive. When the window opens, click Clean up system files (this is the important button, it reruns with admin rights and reveals far more). Tick Windows Update Cleanup, Temporary files, Delivery Optimization files and Recycle Bin, then click OK.

You can also run Disk Cleanup straight from the command line, which is handy for clearing the system files in one go:

:: Open Disk Cleanup straight to the C drive
cleanmgr /d C:

:: Check the size of the hibernation file
powercfg /a

:: Turn hibernation off to delete hiberfil.sys (frees several GB)
powercfg -h off

On my test laptop, Windows Update Cleanup alone freed 21GB. After a year of cumulative updates, this is almost always the biggest single win, and Storage Sense never touches it. Don’t skip the Clean up system files button.

Method 3: Clear temp files and the hibernation file manually

If you want full control, you can clear the temp folders and the hibernation file by hand. This is safe and reversible, and it catches junk the automated tools sometimes leave.

Press Win + R, type %temp% and press Enter to open your user temp folder. Select everything (Ctrl + A) and delete it. Windows skips any files currently in use, which is normal and safe. Repeat with temp (the system temp folder) if you like.

The hibernation file (hiberfil.sys) can be several gigabytes and sits hidden at the root of C. If you never use Hibernate, turn it off with powercfg -h off from an admin Command Prompt (shown above) and Windows deletes the file instantly. You can turn it back on any time with powercfg -h on.

Deleting files from the temp folder is safe: Windows only stores throwaway data there. Anything still in use is skipped automatically, so you can’t break a running program this way.

Here's the workflow:

1. Open %temp%, select all and delete. Skip any file Windows says is in use.
2. Empty the Recycle Bin afterward, since deleted temp files land there.
3. If you don’t use Hibernate, run powercfg -h off as admin to remove the hibernation file.
4. Reboot and check your free space in This PC.

Between the temp folders and turning off hibernation, I recovered another 6GB on my test machine after Disk Cleanup had already run. These are small wins individually but add up, especially on a cramped SSD.

Method 4: Go deeper with BleachBit

Uninstalling apps you no longer use is also one of the fastest ways to reclaim space: see our guide on how to uninstall stubborn programs in Windows if any refuse to budge. When the built-in tools have done their work and you still want more, BleachBit is the free, open-source answer. It clears app caches, logs, browser data and dozens of other junk categories that Windows tools never touch, with no ads, no upsells and no bundled extras.

Download BleachBit only from its official site, bleachbit.org. Open it, and on the left you’ll see checkboxes for categories like system temp, thumbnail cache, browser cache and application logs. Tick what you want, click Preview to see how much each will free without deleting anything, then click Clean to do it for real.

Leave the browser cache categories unticked if you don’t want to log back into sites or lose saved sessions. Everything else BleachBit offers is safe to clear. On my test machine it found another 3GB of app caches and logs after every Windows tool had already run.

Method 5: Find what’s really eating your space with WizTree

Sometimes cleanup tools aren’t enough because one giant folder or file is the real problem. WizTree is a free tool that scans your drive in seconds and shows you exactly what is taking up space, sorted largest first.

Download WizTree from diskanalyzer.com, run it and select your C drive. It reads the drive’s file table directly, so a full scan takes seconds rather than minutes. The results show your biggest folders and files at the top. Often you’ll find a forgotten downloads folder, an old backup, game installers or a runaway log file using tens of gigabytes. Delete what you no longer need, and you may free more space in one step than every cleaner combined.

Reclaimed your space? Turn on Storage Sense so you don’t end up here again, and you’ll never need a paid cleaner. Which tool freed up the most room on your drive?