You can download the entire Stopping your Touch Screen from auto Zooming article here.
Most touch screen technology has a setting which auto zooms the screen display when a user double-taps the screen quickly. This can be annoying when using a Public facing kiosk that does not need this function.
We recommend if using a touchscreen that you go to the Windows Control Panel on the kiosk, select Pen and Touch, select the Touch tab, and un-tick the Enable multi-touch gestures and inking.
This will stop the touch screen from accidentally expanding and contracting the display when visitors accidentally double-tap the screen with their fingers. Just like an iPhone or Android phone, touch monitors are sensitive and are designed to (magnify) increase and decrease display resolutions with double taps.