Anyone Familiar With The Acer Aspire One Notebook?

I lost my manual for my mini netbook. I just wondered if anyone knew how to change the zoom feature. Whenever I accidently hit the mouse pad just the right way, it makes my internet screen zoom in or out. Also, when I am using POwerpoint for class is changes my font size and I am unable to get the font size back to normal even when I change it in the font column. Anyone knowhow to disable this feature all together?