StopComputerWhenNotDownloading.ps1

param(
    $LessThan = 5,
    $ForMinutes = 5
)

$Continuing = $true
$NetBytes = '\Network Interface(*)\Bytes Received/sec'
$Count = 0

while ($Continuing) {
    $Down = (Get-Counter -Counter $NetBytes).CounterSamples.CookedValue / 1MB
    if ($Down -le $LessThan) {
        $Count++
    } else {
        $Count = 0
    }
    Write-Host "$(Get-Date): $($Down)MB/s $(if ($Count -gt 0) {"(Count $Count)"})"
    
    if ($Count -ge $ForMinutes) {
        Write-Host "Shutting down."
        $Continuing = $false
        Stop-Computer -Force
    }

    Start-Sleep -Seconds 60
}