Asus Zenbook UX31A touchpad driver no longer works in Windows 10

I had the same problem, and here's what seems to have solved the problem.

First, I went into the Control Panel (It's in File Explorer from the Start Menu), and I went into Programs and then Uninstall Programs. I scrolled down to the Elan Touchpad program, and when I right-clicked, it allowed me to update the program.

Second, I uninstalled the Asus Smart Gesture program. I downloaded the update for the driver from here: http://support.asus.com/Download.aspx?SLanguage=en&m=smart+gesture (choose the Windows 10 version), and I installed the update.

As far as I can tell, this has restored the touchpad, and I can use smart gestures to scroll and change the magnification.

I hope this helps.