You may want to try to reinstall again with the touch pad enabled, it
could be an issue of a kernel module not loading. Or see if you can
find what exact module needs to load to run the touchpad and go
through making sure that not only the kernel module is loaded properly
but (perhaps more importantly) the xorg.conf file is configured to use
the touch pad as well.

As root, you can try doing a lspci and looking through to find the
hardware that runs the touch pad. On my laptop it is a Synaptics
Touchpad but there are other vendors.