Hi,
Welcome to Microsoft Community and thank you for posting the question. I understand that the touchpad is not working. I will help you with this issue.
1.What is the model number of the computer?
2.Which security software is installed?
3.Did you make any changes to the computer prior to the issue?
In order to troubleshoot this issue, let us try these methods.
Method 1.
You may run the hardware troubleshooter and check.
Run the troubleshooter and check if that helps.
Follow these steps:
a) Press the ‘Windows + W’ key on the keyboard.
b) Type troubleshooter in the search box and then press enter.
c) Click hardware and sound and run the Hardware and Devices Troubleshooter.
d) Follow the On screen instructions.
Method 2.
You may update the touchpad drivers and check the status.
What if a device isn't installed properly?: http://windows.microsoft.com/en-US/windows-8/what-device-isnt-installed-properly
Method 3.
You may check with ASUS support and their forums.
ASUStek Support: http://support.asus.com/
ASUStek Forums: http://vip.asus.com/forum/default.aspx?SLanguage=en-us
ASUStek Drivers: http://support.asus.com/download/download.aspx?SLanguage=en-us
If you need further assistance on this particular issue or any other Windows related issue, let us know and we will be glad to assist you.