System.ServiceProcess.ServiceController[] sc = System.ServiceProcess.ServiceController.GetServices();

foreach (System.ServiceProcess.ServiceController s in sc)
{
    if (s.ServiceName.Equals("MSSQLSERVER"))
    {
         if (s.Status.Equals(System.ServiceProcess.ServiceControllerStatus.Stopped))
         {
                s.Start();
                Console.WriteLine("SQL Server Started..!");
         }
    }
}