I had the same problem... and sound was awful after upgrading to win10, because like with all realtek drivers for the laptops I have used, they have custom software included with the driver (in this case the maxxaudio stuff) returning to the last driver update for the g550jk solved the problem...
The only thing I really don't like much of Asus is that they don't update all the drivers (some of them are the same when the laptop was released and never updated them and also contain custom software in some cases like this)
GO to the support page for your PC, search on the win 8.1 drivers and download it... problem solved(at least on my case) xD