I upgraded to Win10. The built in soundcard, that functioned fine under Win 7 will no longer work. What is puzzling is in Device Manager it shows the driver installed and the device 'working properly'. Yet, when I go to audio devices it states there is no audio device installed. And in order to check if I had the right drivers I installed SiSoft Sandra and it doesn't find a sound card either.

It's a Gateway model MT6451, which Gateway no longer supports.