There are 3 modules of the Dell Latitude series that i know share the same touchpad hardware, instead of writing 7290, 7390 and 7490 i decided to write 7x90 to save space and save me time
For people who installed a windows version Dell says are "unsupported" they'll soon quickly realise the touchpad wont work at all in windows 7 or will work in windows 8.1 albiet very buggy if lucky
I wanted to help such people out
Nothing really, at most probably like that cool zoom feature if you get what i mean
ON WINDOWS 7 YOU WILL LOSE MULTITOUCH DRAGGING, this is fine tho since bringing the trackpad to edge while dragging will make it still drag albeit it slowly
Make sure "Disable Driver Signature Enforcement" is enabled
Make sure you have the "Intel Serial IO" driver installed
Download the repo, find the folder suitable to your windows version and then run "DPInst.exe"
Allow any unsigned driver installs
Press yes to any UAC Prompts
Finished :D