Please follow below steps to proceed.
(1) Enter into device manager.
(2) Choose "USB 2.0... WebCam", and right click to go to "Property".
(3) Click "Detail", and find the PID number in "Value" as shown below.
(4) According to the PID number and the model name, you can find the right driver on the Asus download site: http://support.asus.com/download/download.aspx
(5) Please remember to uninstall the previous camera driver before install the right driver from Asus download site. There're 2 ways to uninstall completely.
a. Uninstall the camera in device manager, and restart the notebook.
b. Uninstall the camera driver in control panel, and restart the notebook.