C#

/// <summary>
       /// This routine updates the start mode of the provided service.
       /// Add Reference to System.Management .net Assembly
       /// </summary>
       /// <param name="serviceName">Name of the service to be updated</param>
       /// <param name="startMode">Manual or Automatic. This parameter could probably use
       /// an enum.</param>
       /// <param name="errorMsg">If applicable, error message assoicated with exception</param>
       /// <returns>Success or failure.  False is returned if service is not found.</returns>
       public bool ServiceStartModeUpdate(string serviceName, string startMode, out string errorMsg)
       {
           uint success = 1;
           errorMsg = string.Empty;

           string filter =
               String.Format("SELECT * FROM Win32_Service WHERE Name = '{0}'", serviceName);

           System.Management.ManagementObjectSearcher query = new ManagementObjectSearcher(filter);

           // No match = failed condition
           if (query == null) return false;

           try
           {
               ManagementObjectCollection services = query.Get();

               foreach (ManagementObject service in services)
               {
                   ManagementBaseObject inParams =
                       service.GetMethodParameters("ChangeStartMode");
                   inParams["startmode"] = startMode;

                   ManagementBaseObject outParams =
                       service.InvokeMethod("ChangeStartMode", inParams, null);
                   success = Convert.ToUInt16(outParams.Properties["ReturnValue"].Value);
                   //custom method
                   errorMsg = GetErrorMsg(success) + "\n Try \"Run as Administrator\" ";
               }
           }
           catch (Exception ex)
           {
               errorMsg = ex.Message;
               throw;
           }

           return (success == 0);
       }