Because I did this one then forgot HTF I did it and had to switch it back on again
me@jaykilleen.com wrote this about 7 years ago and it was last updated about 7 years ago.
sudo nano /usr/share/X11/xorg.conf.d/10.evdev.conf
Add an Option "ignore""on" to the Section InputClass for touchscreen.
Section "InputClass"
Identifier "evdev touchscreen catchall"
MatchIsTouchscreen "on"
MatchDevicePath "/dev/input/event*"
Driver "evdev"
Option "ignore""off"
EndSection