Hi, I am tring to install debian 9 using the offline DVDS, which is the most convenient for me. The menu comes up but none of the options work. It just pauses for a few seconds with none of the keys working and then comes back to life. When I go into the command prompt through the help menu (the only option which works) and try to enter the options there, it says "invalid argument", for each one I try. I have a dell latitude laptop.