you can then run it from System > Administration > Calibrate Touch-screen
after you have calibrated it will show a terminal output that looks similar to this
Warning: multiple calibratable devices found, calibrating last one (eGalax INC. USB TouchController) use --device to select another one. Calibrating EVDEV driver for "eGalax INC. USB TouchController" id=12 current calibration values (from XInput): min_x=0, max_x=4095 and min_y=0, max_y=4095 Doing dynamic recalibration: Setting new calibration data: 77, 3935, 115, 3984 --> Making the calibration permanent <-- copy the snippet below into '/etc/X11/xorg.conf.d/99-calibration.conf' Section "InputClass" Identifier "calibration" MatchProduct "eGalax INC. USB TouchController" Option "Calibration" "77 3935 115 3984" EndSection
in terminal type:
gksudo gedit /usr/share/X11/xorg.conf.d/99-calibration.conf
and copy and the paste the calibrations and save it.