If you notice that there is no sound first make sure the headset is plugged in and the computer finds them as a default device.
To do that click on the windows button, in the search type "Sounds" and open the sound settings, there you will see your recodings devices and Playback devices, if
the headset is plugged in you will see the make and the model of the headset and it should be marked as default device.
If you see this that means that the hardware is recognised from the pc.
The predictive dialer works only with Google Chrome
If you see da red dot in the bottom left corner that means that there is an issue with the sound and it is not going through your browser.
To fix this follow the steps bellow.
1- logout and close the Dialer
2- Open the Chrome settings -> Advanced sttings -> Content settings -> Microphone
3- Make sure the access for your micrphone is allowed, and check which microphone was found fro your browser - should be the same as the one in the sound settings
4- Delete the saved link of the dialer which you seee in the allowed list
5- Open the Dialer in incognito mode -> Login (check the mark for use browser to communicate) -> You will hear a beeping noise and
you will see a popup on the lef upper corner of the broeser (press ALLOW)
6- Check the left bottom corner you should see green dot now
If this does not help please call support