Job.StartEncoding is not working in IIS 7.5

Question

Hello

I am developing a video conference application in Visual Studio Express 2013  Web  using Expression Encoder SDK 4. & .net Framework  4. My application is working quite well in IIS Express 8  but  it is not working in IIS 7.5 . I  am puzzled  for last two days. I continuously googling but unable to get the answer. I tried all firewall blocking & unblocking programs  without success. Please help me since I am new in this . My code is below

 LiveJob job = new LiveJob();
 private LiveDeviceSource devicesource;

 EncoderDevice video = EncoderDevices.FindDevices(EncoderDeviceType.Video).Count > 0 ? EncoderDevices.FindDevices(EncoderDeviceType.Video)[0] : null;
        EncoderDevice audio = EncoderDevices.FindDevices(EncoderDeviceType.Audio).Count > 0 ? EncoderDevices.FindDevices(EncoderDeviceType.Audio)[0] : null;
       
       
            
            if (video != null && audio != null)
        {
            
            devicesource = job.AddDeviceSource(video, audio);
            job.ActivateSource(devicesource);
           
          
            PullBroadcastPublishFormat output = new PullBroadcastPublishFormat ();

            output.BroadcastPort = port;
           job.PublishFormats.Add(output);
                                   
            job.StartEncoding();
          
        }