How to disable touchpad !!

My laptop (Latitude D620) is driving me crazy!!!

How do I turn off the touchpad and disable the top row (between touchpad and spacebar) of mouse buttons?  ?

 When ever I'm in Word, or composing an email, the cursor moves up into previously typed text and starts typing from there instead of where I was at.  I suspect it is the touchpad or the 'mouse' buttons between the touchpad and the space bar.    On a ThinkPad there was way to turn off the touchpad, but still leave the joystick/pointer enabled.  That's what I want to do.  But I need to also disable the top row of mouse buttons.

In other words what I want is a set up where the joystick/pointer works and the bottom row (below the touchpad) of mouse buttons works, but not the touch pad itself, or the top row of buttons.

 It sounds funny, but it has become a severe productivity issue.  The cursor jumping has happened 7 times just in this one email !!