there is a shortcut on your keyboard somewhere to turn touchpad on/off.
Look at the blue icons on the F1-F12 buttons, and try those that you not sure what they are for. Typically touchpad will have something like a square with a finger pointing at it icon, or could be something similar. I can't find a manual or full size picture of the keyboard layout.
If you're still unsure, if you can make a top down picture of your full keyboard and upload it, that could help with the issue.
EDIT: according to the manual I found here:
http/www.generalmanual.com/Notebooks/Asus-F5R-Notebook.htm
the laptop has media keys next to the power button, one of those keys features an outline of a touchpad (big rechtangle on top of two smaller ones) with a line going across it (like a cross out). that's the button to activate/deactivate the touchpad