You cannot really work with this laptop, if you cannot disable the touchpad.
The touchpad on this model registers as id=15,
Virtual core pointer id=2 [master pointer (3)]
⎜ ↳ Virtual core XTEST pointer id=4 [slave pointer (2)]
⎜ ↳ ImPS/2 Logitech Wheel Mouse id=15 [slave pointer (2)]
⎜ ↳ Logitech USB Receiver id=12 [slave pointer (2)]
⎣ Virtual core keyboard id=3 [master keyboard (2)]
When I try to configure via kde->configure->desktop->keyboard, mouse->touchpad
it says that “the synaptic driver” is not loaded.
synclient (and syndaemon) says the same:
synclient -l
Couldn’t find synaptics properties. No synaptics driver loaded?
I already includes " Option “SHMConfig” “true” " in
/etc/X11/xorg.conf.d/20-synaptics.conf
Simply unloading the psaux kernel-module doesn’t work as the module is in the kernel. (sound weird, but you know what I mean 
)
Please, how can I do it?
Check /var/log/Xorg.0.log to see what is actually loaded.
34.193] () ImPS/2 Logitech Wheel Mouse: Applying InputClass “evdev pointer catchall”
34.193] () ImPS/2 Logitech Wheel Mouse: always reports core events
34.193] () ImPS/2 Logitech Wheel Mouse: Device: “/dev/input/event4”
34.197] (II) ImPS/2 Logitech Wheel Mouse: Found 3 mouse buttons
34.197] (II) ImPS/2 Logitech Wheel Mouse: Found scroll wheel(s)
34.197] (II) ImPS/2 Logitech Wheel Mouse: Found relative axes
34.197] (II) ImPS/2 Logitech Wheel Mouse: Found x and y relative axes
34.197] (II) ImPS/2 Logitech Wheel Mouse: Configuring as mouse
34.197] () ImPS/2 Logitech Wheel Mouse: YAxisMapping: buttons 4 and 5
34.197] () ImPS/2 Logitech Wheel Mouse: EmulateWheelButton: 4, EmulateWheelInertia: 10, EmulateWheelTimeout: 200
34.197] (II) XINPUT: Adding extended input device “ImPS/2 Logitech Wheel Mouse” (type: MOUSE)
34.197] () ImPS/2 Logitech Wheel Mouse: (accel) keeping acceleration scheme 1
34.197] () ImPS/2 Logitech Wheel Mouse: (accel) acceleration profile 0
34.197] () ImPS/2 Logitech Wheel Mouse: (accel) acceleration factor: 2.000
34.197] (**) ImPS/2 Logitech Wheel Mouse: (accel) acceleration threshold: 4
34.197] (II) ImPS/2 Logitech Wheel Mouse: initialized for relative axes.
34.197] (II) config/udev: Adding input device ImPS/2 Logitech Wheel Mouse (/dev/input/mouse0)
It looks like the tochpad is not identified properly. It is loading the evdev driver instead of the touchpad driver.
You can see the output of the lshal to see what are the identifiers for your device and you can create a configuration file accordingly since you don’t need the touchpad functionality.