Touchpad on Dell Lattitued E7450 always moved cursor during typing

After getting a new Laptop "Dell LATTITUDE E7540" with Windows 8.1 PRO, I had very often
a problem when coding in an IDE or writing text in an editor or using Word.

During Coding the hand hit somehow the touchpad and the mouse cursor moved and a
typed somewhere in a completely different place. ( Ctrl-Z for Undo was always a great help ;-)

After a little bit searching for deactivating the touchpad ( which is not my favorite, because of
using the laptop without a mouse ), I found the Settings:

Start the Control-Panel and select "Hardware and Sound" in the next window select the link for
the mouse ( see step 1 above ) after this selct 2 - the Dell Touchpad settings and then on the slider,
I moved to the max ( 3 ) and now the touchpad doesn't react so far on my typing.