$dg=9956
$alarm= $false
$disks = Get-CimInstance CIM_LogicalDisk | 
? DriveType -eq 3 | select name,@{n='FreeMB';e={$_.FreeSpace/1MB}}
foreach ($disk in $disks) {
    if ($disk.FreeMB -lt 9956){
        $disk.FreeMB
        $alarm=$true
    }
}

if ($alarm) {Write-Host 'ALARMMMMMMM!!!!!' -BackgroundColor Red}
else {Write-Host 'OK' -BackgroundColor Green}

https://bitsforclicks.com/?r=AS8ARY2T0EW33E3