1. Right-click the Sound icon located in the lower right corner of your desktop. (The icon looks like a small speaker).
2. Click “Playback Devices” on the menu:
3. Now the Sound Window opens, make sure the Playback tab is selected. Right-click “Realtek HDMI Output” playback device and click "Enable” from the drop-down menu. See Fig.2
After the above operation, you should be able to enjoy HDMI audio from your computer to your TV.
(If there is no sound at all after enabling the device, please uninstall the VGA/Video driver and update/ install the latest driver.