Windows – Huge amount of “amd64_” files in winsxs 8.93GB, what are they

Good you ruled out the possibility of hidden or system files not being calculated in the file size sum. Some other things to check:

• Disk corruption: run a chkdsk -f on the disk. Maybe there is a corruption of the filesystem and the FAT (or the MFT, the NTFS equivalent) thinks disk space is allocated while it isn't.

• Invalid free space reporting: NTFS stores the free space in its metadata. It's possible it's invalid. A chkdsk -f should fix it too.

• Insufficient permissions: is your user allowed to see and access all files on the disk?

A quick and dirty powershell script to do what you need, you'll need 7zip commandline version. Just change the two paths in the sript and TEST it first, don't have the opportunity to do so myself at the moment.

$folderPath="X:\Test";

Get-ChildItem $folderPath -recurse | %{ 

    if($_.Name -match "^*.`.zip$")
    {
        $parent="$(Split-Path $_.FullName -Parent)";    
        write-host "Extracting $($_.FullName) to $parent"

        $arguments=@("e", "`"$($_.FullName)`"", "-o`"$($parent)`"");
        $ex = start-process -FilePath "`"C:\Path\To\7zip\7z.exe`"" -ArgumentList $arguments -wait -PassThru;

        if( $ex.ExitCode -eq 0)
        {
            write-host "Extraction successful, deleting $($_.FullName)"
            rmdir -Path $_.FullName -Force
        }
    }
}