$ports = @(4000, 3000, 3001)
$killed = @()
Get-NetTCPConnection -State Listen -ErrorAction SilentlyContinue |
  Where-Object { $ports -contains $_.LocalPort } |
  ForEach-Object {
    $pid = $_.OwningProcess
    if ($killed -notcontains $pid) {
      Stop-Process -Id $pid -Force -ErrorAction SilentlyContinue
      $killed += $pid
    }
  }