I have an external hard disk, and for some reason, it is reporting wrong free space.

In Windows Explorer, it is showing the used space is 378 GB.

Free space from Windows Explorer

I tried running chkdsk H: /f /r, it seems to report the same usage as Windows Explorer, and it says that there is no problem.


But when I tried selecting all the files inside this drive, it is showing much lesser usage.

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I've already set the setting to show all hidden files and folders, also show the protected OS files, but it still cannot find about those missing files. And the difference is huge (282 GB). I've already cleaned the Recycle bin as well.

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What I am missing here and how do I identify those missing spaces?

[UPDATE]: I used this tools to help identify and it seems to find some gigantic files, of which filename is quite weird. Anyone knows what this is and is it safe to delete?

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  • Free space and used space adds up? 368+162=540?
    – Moab
    Aug 29, 2016 at 0:04
  • Used space is 378 and free space is 162, so it adds up to 540. So the total is correct. But the used space is not correct.
    – rcs
    Aug 29, 2016 at 0:18
  • 1
    There are hidden files that never show up using properties.... superuser.com/questions/212647/…
    – Moab
    Aug 29, 2016 at 0:24
  • If you look at the 3rd screenshot the checkbox for hidden has a square instead of a tick mark: that means not all hidden files are counted. Some are omitted, I'm not sure which ones but seems like a lot. What the show hidden files option does is display them in your file explorer, and does not necessarily count the in the adding up of used space. Try bringing up the dialog on the 3rd screenshot after launching explorer.exe as administrator. But I do not think it's designed to be an accurate measurement of all filed on disk.
    – user628797
    Aug 29, 2016 at 0:27
  • 1
    The cause for mis-representation of file storage usage is security - "Run as Administrator" is required for the 3rd-party applications to access folders you can't measure without this privilege.
    – Alocyte
    Dec 10, 2020 at 12:25

5 Answers 5


I had the same problem, but a different cause. In my case when I tried to select all the files on the C:\ partition, the used space was 70 GB, but the Windows Explorer was showing 210 GB of used space.

I have looked on the internet, but no answer seemed to be helpful. I didn't have backup enabled nor old copies of windows installed.

I decided to download a disk usage analyzer called WinDirStat and I instantly had the missing space. It was a MSSQL .mdf file that was taking about 140 GB. Deleted that file and everything got back to normal.

  • But OP had already found the cause
    – yass
    Jun 4, 2017 at 19:27
  • 10
    Yes, I know. Just in case anybody look for this problem and the cause is different from the OP. Jun 5, 2017 at 8:14
  • 4
    @yass: The causes of this problem are numerous so this intervention from Marius is welcome.
    – AlainD
    Oct 30, 2018 at 9:44
  • Note: If WinDirStat shows a lower total used space on a drive than Windows reports, you might need to run WinDirStat as Administrator and/or set File Explorer to show hidden and system files.
    – Paul Smith
    May 24, 2021 at 22:05

It appears to be the System Restore that take this space. I go to Control Panel > System > System Protection > (select drive) > Configure and find out the huge size of the system restore file. It is quite weird though that the file is found in (E:) instead of (H:), despite taking the size from (H:). After clearing the system restore then I manage to get back the free space. I did remove the system restore file from (H:) as well.

Another weird thing is that the system restore is disabled for this drive (see the radiobutton selected), but despite that, it still create the system restore file.

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  • 1
    System Restores can be useful, so a good practice is to leave it on, with a relatively small usage like 10 GB . Oct 12, 2017 at 19:51
  • Agree, this answer really needs a caveat Disabling system protection will prevent you rolling back to a previous state when issues are encountered with windows, likely necessitating a full reinstall of Windows and ALL installed programs at the cost of many hours of work. System restore is always on the boot drive (one containing Windows), so that Windows can be sure if you are in the recovery environment (also stored on the boot disk), you should also have access to the system restore info, while not having to worry about RAID, or some other thing that complicates access to other drives.
    – user66001
    Jun 28, 2019 at 14:34

Properties is correct. Empty your recycle bin. On my system the $Recycle bin is invisible. Windows will then display the correct smaller number.


Get a decent file manager to show you what's where. Windows will show various things inconsistently, as explained in the other answers.

Alternately, utilities like DiskState can show you very detailed information in a very organized manner (as in per-subfolders).

  • I already found it, it is due to the system restore, and after I cleaned it, the free space is back.
    – rcs
    Aug 29, 2016 at 13:05

sometimes its hidden folders like an aria-debug files that can take huge space which of course are because of bugs in it . i deleted an aria-debug file that took 157 GB and my computer is still great i heard its something connected to Microsoft onedrive which is a cloud service so its realy cant harm to delete it..

  • Deleting something without proper understanding of what it is can leave the computer unbootable!
    – user66001
    Jun 28, 2019 at 14:20

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