on many hp and compaq laptops there is a button or spot on the touch pad it self(hold your finger over a light) that turns the pad on and off as well.
Some touch pads also have an option on there drivers to disable touch while typing, this just disabled it while typing and for a few seconds after tying so you do not move all over.
what laptop is it?
It is a dell about 3 years old. I';ve tried everythiing and cannot disable it. But I don't know much about computers. I have tried the suggestions from Tom's Hardware