With no computer information to go by, the only suggestion I can give is to check Window's Sound Panel and see if the Main Audio Device you want working is "Default".
Also in Sound Panel see if your Motherboard's Audio is enabled as well as your GPU Graphics Audio. Since you are using your Motherboard's Audio drivers (Front and Rear Ports) whatever you have connected to the Audio port should be your default "main audio device" to get sound from.
Also check Device Manager and see if your Motherboard's Audio drivers are enabled and working without any errors.
