I installed a raspberry pi 3, a 19-inch touch screen, but I did not walk the mouse correctly.
Thanks for the help.
They probably meant that the cursor doesn't work properly.
The OP is probably referring to touch screen calibration. Raspbian default has a very basic single touch driver which just moves the mouse pointer to the touch point. I tried using my 23" touch screen with USB touch interface. The calibration was OK in center of screen but got progressively worse going to the edges of the screen..Several cm out at the edges. There are touch calibration tutorials on Google but never tried as I don't normally use any RPi with the large touchscreen.