Installation of Mx-key is very easy if u follow up this following guide, first of all install latest version of mx-key software setup-
Then, after plug in mx-key usb dongle which will ask for the drivers, then give its correct path like this way- C:\mobileEx\3.3\data\drivers\card\FT2K
Then install usb cable drivers of ufs /jaf or hwk or any fbus interface or for nokia usb data cable can also to be used, when you refresh mx-key device it will ask for ufs obsolete drivers, press yes option, then computer will ask for restart
after restart open mx-key, it will ask for sign up application with internet online, it will take 2 minutes to make mx-key signed application updation
After this , you have also to update licenses once of your mx-key dongle for full access of this great device. After this all just connect the fbus interface and which particular tool want to use, just go in option and open that tool.