Just a question...and suggestion.
If the original operating system for that unit was another one other than the one installed currently, you may have download those drivers
If not, I have seen those settings pretty hidden in a spot you may not even think they may live in.
Create a restore point, and do some playing around exploring with your system menus. The worse that can happen is you don't find it, change a few settings, and then just revert back to the restore point. Also make sure you are using just one finger as far right as possible on the touchpad to make sure that it's not active already and we're just overlooking something.
One last thing, go to control panel and type mouse. Some of these settings are hidden under mouse an not touchpad. GOOD LUCK!