I have Inspiron 15 5567 Windows 10 64 bit . Yesterday my laptop was on sleep for about 2 hours, later when I opened it, the volume symbol on the left at the taskbar had a red cross along side it which showed no audio output device installed. There was no audio at all when I played some videos or songs. So I followed the discussion at Dell Community and the solution given by Chinmay-S actually worked. But today again after starting my laptop from almost about a 2 hours sleep, it is showing the same problem, I have already tried the solution i.e installing the audio driver but it is of no use now. Moreover in the device manager there is no option for Sound , Video and Game Controllers. 

Thanking you in Advance