How to Find Large Files Taking Up Disk Space
Large files taking up disk space are rarely the ones people expect. The drive is usually full because of something that never appears in a normal folder view, such as the hibernation file, restore points, or driver packages left behind by hardware you no longer own. So start with the built-in storage views to see where the space went, then hunt the actual files with a size filter and a disk analyser. The order matters, because deleting the wrong file in the wrong place can cost you a working system. Both halves take a few minutes, and every tool involved is already on the machine.
Start with the storage breakdown in Settings
Windows already knows roughly how much space each category occupies, and reading it takes under a minute.
- On Windows 11, open Settings > System > Storage. The page shows the system drive as a bar with category bars underneath for apps, documents, pictures, audio and video, and other files.
- Choose Advanced storage settings at the bottom of that page to see every drive on the machine, each with its own usage bar. Windows 10 shows the same per drive breakdown directly on Settings > System > Storage.
- Windows 10 lists the categories as apps, documents, pictures, audio and video, video, and other, with a Temporary files button below. Windows 11 puts the same button in the same place.
- Click a category to open a list of the applications or folders that make it up, where the estimate becomes a list you can act on.
Read the bars before you open anything. A machine with 40 GB of videos in the video category needs a different conversation from one where the space went into other, where virtual disks and system files are counted.
Run the temporary files cleanup
The Temporary files panel is the fastest safe win available on Windows. It is a list of categories with checkboxes, and you decide what gets removed. Windows preselects the safe ones and deliberately leaves the risky ones unticked.
- Delivery Optimization Files holds copies of update and app data shared with other Windows machines. Safe to remove.
- Windows Update Cleanup holds superseded update files left behind after an install. Safe, and it can be several gigabytes.
- Temporary files are leftovers from apps and installers. Safe.
- Thumbnails are cached preview images. Safe, they rebuild on demand.
- DirectX Shader Cache is compiled shader data used by games and video playback. Safe, it rebuilds as well.
- Recycle Bin holds everything you deleted and have not emptied. Tick it only if you want that space back.
- Downloads is usually left unticked, and for a good reason. Tick it and Windows deletes the contents of your Downloads folder, including installers you have not run yet.
Press Delete files and wait for it to finish. On a machine that has not been cleaned in a long while, this panel is often where several gigabytes come from. The Configure button next to it opens the system files view, which adds entries such as Previous Windows installation(s).
The classic tool gives you the same choices in more detail. Type Disk Cleanup in the Start menu, choose the drive, and click Clean up system files to see the full list.
Find the actual big files
Category totals tell you which folder to open, not which file to remove. Search handles that part.
- Open File Explorer and go to the drive you care about, usually This PC > Local Disk (C:).
- Click in the search box on the right of the address bar and type
size:>500MB. Windows search understands that filter and returns only the files above 500 megabytes. Change the number to your own threshold, andsize:>1GBworks the same way. - Switch to Details view, then right click the Size column header and sort by size, largest first.
- Scope the search to the folder you actually care about, such as
C:\Users\YourName\Downloads, rather than This PC. Searching This PC walks every drive and takes far longer.
Windows search also understands a kind: filter, for example kind:=video. Combining the two operators, kind:=video size:>500MB, finds the video files that are eating a drive without listing everything else. Searches run faster on indexed locations. If one is slow, add the folder through This PC > Properties > Indexing Options > Modify.
The space Windows keeps out of sight
Four locations hold serious amounts of space that never show up in a normal folder view. None of them are junk, so each needs its own handling.
hiberfil.sys
This is the hibernation file. Windows hides it and protects it because it holds the memory image used for hibernation and for Fast Startup. Its size depends on your RAM and on the hibernate settings, and on many machines it lands around 75 to 100 percent of installed memory, so a laptop with 16 GB of RAM can carry a 12 GB file on the system drive.
Turn it off from an elevated Command Prompt:
powercfg /hibernate offThe file is deleted on the spot. The catch is that Fast Startup depends on the hibernation file, so this command switches Fast Startup off as well. Put it back later with powercfg /hibernate on.
pagefile.sys
The page file is the swap area, and Windows sizes it according to your RAM and workload. You can move it to another drive through Settings > System > About > Advanced system settings > Performance > Settings > Advanced > Virtual memory. Do not set it to no paging file on a machine with limited memory, because that is how a computer learns to freeze under load. Letting Windows manage the size is a sensible middle ground.
System Volume Information
This folder holds restore points and shadow copies, and its size is controlled by System Protection. Open System > About > Advanced system settings > System Protection > Configure to set a maximum percentage for shadow copies, or turn system protection off on a drive where you do not want restore points. The same dialog opens from the Configure button in the temporary files panel.
WinSxS
The WinSxS folder under C:\Windows holds the component store, and it always looks far too big. Do not delete or empty it by hand. Windows keeps hard links there, and removing files by hand breaks Windows Update and optional components such as .NET Framework 3.5.
Run the supported cleanup instead, from an elevated Command Prompt:
DISM /Online /Cleanup-Image /AnalyzeComponentStore
DISM /Online /Cleanup-Image /StartComponentCleanupThe analyse command reports how much space the cleanup would recover and whether a deeper purge is recommended. Adding /ResetBase removes superseded versions outright, but it also takes away the option of uninstalling recent updates.
Clear the Windows Update download cache
Windows keeps downloaded update files in C:\Windows\SoftwareDistribution\Download, and that folder can hold several gigabytes of installers it has already applied. Clearing it forces Windows to download them again, so only do it when you have a decent connection and genuinely need the space.
Open an elevated Command Prompt, stop the services, and rename the folder:
net stop wusa
net stop bits
ren "C:\Windows\SoftwareDistribution\Download" "Download.old"Reboot and let Windows Update redownload what it needs. When the update completes, the Download.old folder is safe to delete.
Use a disk analyser for the full picture
Settings gives you category totals and search gives you individual files. A disk analyser shows the whole tree at once and finds folders you never thought to look in.
- WizTree reads the master file table directly, so a scan of the whole of C: finishes in seconds and it shows the largest folders and files straight away.
- TreeSize Free builds a folder tree that you can sort and save for comparison against a later scan.
- WinDirStat draws a treemap where the biggest blocks are the biggest folders, which makes a runaway downloads folder obvious.
One warning applies to all three. Run them on a healthy drive, because a full scan of a disk with unreadable sectors takes forever and can push a failing disk further. If the machine has been slow or crashing, how to check SSD and HDD health in Windows comes first. Before you delete anything at scale, get your important files onto a second drive with how to back up important files on Windows.
What is safe to delete and what is not
| Location | Safe to remove? | Notes |
|---|---|---|
| Downloads folder contents | Usually | Check for installers and files you still need |
| Recycle Bin | Yes | Empty it if you want the space back now |
| Temporary files, thumbnails, shader cache | Yes | All three rebuild on demand |
| Windows Update Cleanup | Yes | Removes superseded update files |
| hiberfil.sys | Only through the command | Use powercfg /hibernate off, and lose Fast Startup |
| pagefile.sys | Only after resizing or moving it | Never disable paging on a small memory machine |
| C:\Windows\WinSxS | No | Use DISM StartComponentCleanup instead |
| C:\Windows\System32 | No | Core system files and the driver store live here |
| C:\Windows\Installer | No | Uninstallers and repair data live here |
| C:\Program Files | No | Use the uninstaller in Settings instead |
| System Volume Information | Manage, do not delete | Change the limit in System Protection |
Anything under C:\Windows or C:\Program Files that you did not create yourself should be left alone. When a program does offer an uninstaller, use it, because it knows which files belong to the application.
Old driver packages are worth a mention too. They accumulate in C:\Windows\System32\DriverStore\FileRepository, and leftovers from hardware you no longer own can run to several hundred megabytes. Removing them by hand breaks your rollback option, so use the cleanup your graphics driver package provides. How to update graphics drivers safely covers keeping a working driver and rolling back when the new one misbehaves.
Frequently asked questions
How do I find large files on my C drive quickly?
Open File Explorer, go to the C drive, click in the search box, and type size:>500MB. Windows returns only the files above that size. Sort the results using the Size column in Details view to see the biggest first, and narrow the search to one folder such as Downloads so it does not walk every drive.
What is hiberfil.sys and can I delete it?
It is the hibernation file, and Windows hides and protects it deliberately. Do not delete it by hand. Run powercfg /hibernate off from an elevated Command Prompt, which removes it properly. That also switches off Fast Startup, so put it back with powercfg /hibernate on if you want the faster boot times.
Is it safe to delete the WinSxS folder?
No. It holds the Windows component store and shared hard links, and removing files from it breaks Windows Update and optional components such as .NET Framework 3.5. Run DISM /Online /Cleanup-Image /StartComponentCleanup from an elevated Command Prompt instead. Run DISM /Online /Cleanup-Image /AnalyzeComponentStore first to see what the cleanup would recover.
Why is Windows Update taking up so much space?
The download cache in C:\Windows\SoftwareDistribution\Download keeps the installers Windows has already applied, and it can grow to several gigabytes. The Temporary files panel in Settings clears it for you with the Windows Update Cleanup checkbox ticked. To do it by hand, stop the wusa and bits services and rename the Download folder, then reboot.
What to remember
- Read Settings > System > Storage before deleting anything, so you know which folder is responsible.
- The Downloads checkbox in the temporary files panel is unticked on purpose. Read it before you tick it.
size:>500MBin the File Explorer search box finds the big files quickly.powercfg /hibernate offremoves hiberfil.sys and switches off Fast Startup at the same time.- Never touch WinSxS or System32 by hand. DISM has a supported cleanup for the component store.
- Check disk health before you scan a drive that has been misbehaving, and back up before a large cleanup.
Open Settings > System > Storage and read the category bars, then run the size:>500MB filter on the folder that looks worst. Those two steps tell you the size of the problem and hand you the files to act on.