Hi ponyfan:
Welcome to the HP forum!
Thank you for your inquiry. I will do my very best to help!
I perceive that after updating to Windows 8.1, your Dolby DTS is not working. You tried uninstalling and reinstalling the driver but there was no change. I suggest you run the HP Support Assistant to aid in updating drivers. I would then check Device Manager and ensure you have the latest drivers from the HP website. HP Pavilion 17-e020us Notebook PC Driver. Please respond with the results.
