Wallflower75: I suspect your problem is that you need to work your way through a
tutorial on using a command shell to boss your computer around. (Hint: read the first intro which explains the difference between a graphical user interface and a command shell like the DOS command prompt, then skim ahead to section 20 -- reading stuff that's unfamiliar -- which is where the introduction to using the command line begins.
MobiDeDrm is a command line tool; you need to know where it is, how to invoke it by pathname (and if necessary by telling Python to run it), and how to tell it the name of a file to convert (and where it is). You're not going to get anywhere with it unless you acquire the basics of using a command line (be it the Windows command.exe one, or the Linux shell).