Download synaptics drivers & software. I also recommend twofingerscroll, which provides very useful features like two finger tap, left then right tap, swipe for back & forth, etc. Also, two finger scrolling (a la tablets) is incredibly smooth in Chrome and certain other programs.
Remembered that it's not easy to find the latest version:
http://lifehacker.com/5943337/twofingerscroll-dramatically-improves-windows-touchpads has a link to 1.0.9 with everything fine-tuned. I have had 2 or 3 occasions in the past year or so where features for both synaptics and twofingerscroll must've interfered and locked out any features. A simple restart of those 2 software solved the problem.
You might want to be careful, Asus switched from Synaptics to Elan for their touchpads.