В этой команде, что такое "-gt 1" и "-f".
Get-PSDrive | ?{$_.Free -gt 1} | %{$Count = 0; Write-Host "";}{$_.Name + ": Used: " + "{0:N2}" -f ($_.Used/1gb) + “Free: " + "{0:N2}" -f ($_.Free/1gb) + " Total: " + "{0:N2}" -f (($_.Used/1gb)+($_.Free/1gb)); $Count = $Count + $_.Free;} {Write-Host ""; Write-Host "Total Free Space " ("{0:N2}" -f ($Count/1gb)) -BackgroundColor magenta}