Method for Touchpad detection in Linux Mint Katya & Linux Mint Debian Edition.

a)  For no touchpad detection in LMDE or Katya - you need to edit grub.
 

Go to terminal, enter line  'sudo gedit  /etc/default/grub

find a line  GRUB_CMDLINE_LINUX =" "

Enter this line  i8042.reset i8042.nomux i8042.nopnp i8042.noloop

it should look like this  GRUB_CMDLINE_LINUX="i8042.reset i8042.nomux i8042.nopnp i8042.noloop"

Save the file and close gedit window.

now you need to update the grub configure. So enter in terminal  sudo update-grub

after its done

reboot.

Now your touchpad would start working. in LMDE vertical scroll will also work without doing step 'b'.

If not! continue.

b) Touchpad working but no vertical scroll (mostly in Linux Mint Katya)

Go to terminal, enter the line below

echo "options psmouse proto=imps"|sudo tee -a /etc/modprobe.d/psmouse.conf; sudo modprobe -r psmouse; sudo modprobe psmouse

enter your user password

exit the terminal

Now your touchpad will have vertical scroll working properly.

More help for Sony Vaio user https://help.ubuntu.com/community/Laptop/Sony/Vaio/FSeries/Natty