I needed to check to see if Asus had supported 8.1 drivers for your machine, which it does not, so it would be fair to conclude that the problem might stem from that. I've forced drivers into non supported hardware in the past, but it doesn't always work, but I couldn't relate to you all the "crazy" tricks I've used, but there is one that is easy for you to try, if you'd like to.
I'm assuming that you have downloaded several driver versions, so you may make several attempts.
It goes like this. Sometimes, you'll download a driver zipped folder and once you extract it, you are left with several folders and files.
Invariably, you use the "setup" application and the installation begins.
In this case, instead of doing it that way, you'd go to the device manager, uninstall the present driver, and reboot.
After booting back up, you go back to the device manager, click on the properties of the device and follow the path to installing a driver, usually referred to as updating your driver.
You will get a Window that allows you to direct Windows to a particular folder, and that's exactly what you would do, allowing Windows to find what ever files it needs for that component, from one of the Driver folders.
You can go through this procedure with the various drivers you've downloaded, until one of them works properly.
I hope we get lucky..
Let me know how it goes.
All is well in Paradise.