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C: Drive 40 GByte space unaccounted for

Anonymous
2021-08-08T15:06:20+00:00

I own a high end laptop that, unfortunately, only has a 250 GByte SSD and it is now becoming rather full (179 GB out of 237 GB used). I have recently found that the total sum of the files stored on the disk is about 40 GBytes less than the 179 GBytes given in the C: drive properties by File Explorer. I have checked this in many different ways:

  1. Highlighting all folders and files, including hidden files, and right clicking properties - this gives 141 GBytes used
  2. WinDirStat show 137.9 GBytes used and 41.5 GBytes unknown space
  3. I have checked this using PowerShell and Treesize Free and this give approximately the same results. Note that the 141 GBytes used according to File Explorer includes hyberfil.sys (3.3 GBytes), pagefile.sys (3.7 GBytes) and swapfile.sys (17 MBytes) so these do not account for the unknown space.

My question is where have the unknown approx 40 GBytes gone? I have already tried:

  • Using the windows disk clean-up on both user and system files. I have repeated this using CCleaner and ISumSoft System Refixer. The space saved is included in the above totals and in any case was much less than 40 GBytes
  • I manually searched the disk for space that could be saved (such as deleting old game save files). Again the space saved is included in the above totals and in any case was much less than 40 GBytes.
  • I carried out a full virus scan using Windows defender and no infections were found
  • I have used chkdsk twice - again no problems were found
  • I tried re-installing windows 10 but retaining the apps and files - this made virtually no difference.
  • Having run out of options, I tried reinstalling Windows and not keeping apps or user files (I back these up on OneDrive). I was surprised to discover that there was still about 40 GBytes of unknown space over and above the space Windows and remaining other files took up. Fortunately, I have backed up the disk prior to reinstalling windows using AEOMI backup and I was able to restore the system fairly readily (thank you AEOMI).
  • As a cross-check I carried out the same exercise using my, separate, desktop PC. This showed an overall used space of 234 GBytes and a 'sum of files' of 189 GBytes - that is about 45 GBytes of space unaccounted for.

I have run out of options - can anyone help? Does Windows 10 come with 40 GBytes of deeply hidden files?

Windows for home | Windows 10 | Files, folders, and storage

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  1. Anonymous
    2021-08-21T18:14:12+00:00

    I finally found out how to account for all of the SSD drive space being taken up. I used the Windows 10 supplied storage tool! It is found in Settings > storage and then go to the bottom of the list and click 'Show more categories'. This produced the following breakdown and this adds up to the total that the C: drive disk use also gave. It looks as though the 'System and reserved ' category is larger than any of the free tools available on-line allowed for.

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  2. Anonymous
    2021-08-09T11:48:11+00:00

    Hi Again Dave,

    Screenshot of restore configuration below:

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  3. DaveM121 892.6K Reputation points Independent Advisor
    2021-08-09T11:32:02+00:00

    Hi Ron,

    This is very strange.

    Click your Start Button, then just type restore.

    Open System Restore, select the C drive and click Configure, what space is set aside for system restore on your PC, is that just 1.1GB?

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  4. Anonymous
    2021-08-08T20:12:31+00:00

    Dave,

    Thanks for your help - running TreeSize as Admin found 155 GBytes of files. Unfortunately, File Explorer still shows179 GBytes used (see screen shots below for both). Can we find the remaining 24 GBytes?

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  5. DaveM121 892.6K Reputation points Independent Advisor
    2021-08-08T15:43:57+00:00

    Hi Ron,

    I am Dave, I will help you with this.

    You mention you have TreeSize installed on your PC, right click the icon on TreeSize and select 'Run as Administrator.

    Please provide a screenshot of that TreeSize window.

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