The environment is Window 7 Pro 64 bit with all of the latest updates running in a Dell Studio 17 laptop with internal JBL Speakers. I connected a Logitech 390 USB Headset to work with Dragon 13 for transcription service. All worked very, very well. However, when I disconnected the USB Headset, my internal speakers no longer produce sound. The system rcogizes them as the "Default" audio output device but no sound. When I reconnect the USB Headset, the sound can again be heard from them. I then "Unistalled" the USB Headset with the device manager but still no sound.