Get-DiskUsage

Windows: Reports logical disk usage and free space

Script

#Requires -Version 5.1

[CmdletBinding()]
Param
(
    [string]$ComputerName = $env:COMPUTERNAME,

    [string]$DriveLetter,

    [pscredential]$Credential
)

Process
{
    try
    {
        $session = $null
        $cimParams = @{
            'ClassName'   = 'Win32_LogicalDisk'
            'Filter'      = "DriveType = 3" # Local Disks only
            'ErrorAction' = 'Stop'
        }

        if (-not [string]::IsNullOrWhiteSpace($DriveLetter))
        {
            $cimParams.Filter += " AND DeviceID = '$DriveLetter'"
        }

        if ($ComputerName -ne $env:COMPUTERNAME)
        {
            $sessionParams = @{
                'ComputerName' = $ComputerName
            }
            if ($null -ne $Credential)
            {
                $sessionParams.Add('Credential', $Credential)
            }
            $session = New-CimSession @sessionParams
            $cimParams.Add('CimSession', $session)
        }

        $disks = Get-CimInstance @cimParams

        $results = foreach ($disk in $disks)
        {
            $totalGB = [math]::Round($disk.Size / 1GB, 2)
            $freeGB = [math]::Round($disk.FreeSpace / 1GB, 2)
            $usedGB = [math]::Round($totalGB - $freeGB, 2)
            $percentFree = [math]::Round(($freeGB / $totalGB) * 100, 2)

            [PSCustomObject]@{
                Drive        = $disk.DeviceID
                VolumeName   = $disk.VolumeName
                TotalGB      = $totalGB
                UsedGB       = $usedGB
                FreeGB       = $freeGB
                PercentFree  = $percentFree
                ComputerName = $ComputerName
            }
        }

        Write-Output $results
    }
    catch
    {
        throw
    }
    finally
    {
        if ($null -ne $session)
        {
            Remove-CimSession $session
        }
    }
}

Customize

ComputerName string

Specifies the name of the computer to query. Defaults to the local computer.

env string

DriveLetter string

Specifies a specific drive letter (e.g., "C:") to query. If omitted, all logical disks are retrieved.

Credential pscredential

Specifies a PSCredential object for remote connection.