ServiceController[] NonDevice_services; 

            //GetServices method will retrieve non device driver services only
            NonDevice_services = ServiceController.GetServices();

 //if you want to retrieve services from a particular machine the give machine_name as parameter to GetServices method
//like :-    NonDevice_services = ServiceController.GetServices("myMachine");

            for (int i = 0; i < NonDevice_services.Length; i++)
            {
                lstNonDevice.Items.Add(NonDevice_services[i].ServiceName);
            }

            //retrieve device driver services
            ServiceController[] device_Services;
            device_Services = ServiceController.GetDevices();
            for (int i = 0; i < device_Services.Length; i++)
            {
                lstDevice.Items.Add(device_Services[i].ServiceName);
            }