Can't get my resolution higher than " 1024 * 768 " while my native resolution should be 1980 * 1080. Also it says that it can't recognize my display "Unknown display" . using dell inspiron 15R 5520 i'm connected to the second display via a vga cable attaching the output for the command: $ lspci | grep vga
That would be an issue with your graphics card driver. The fix would be to install the driver appropriate driver for your gpu. Unfortunately there is no easy way to do it as I'm in your same situation with my AMD gpu, if you're running Nvidia you might have more luck, a Google search might turn up a fix.