Okay so I tried to change the .ini file to see if anything goes better when I launch the menu. Nothing happened, I still have this eerie gray bar in the middle of the menu. I've closed my post-it note to check if it was disturbing the game's resolution, it didn't. I have set the graphics on Low, Medium and High (thanks to your "DetailLevel" linecode), no sign of improvement.
However I've noticed that when I press the Start button for Windows and when I go back to the game, the gray bar suddenly turns into the selectable menu I've been looking for. This would be good news if I could select anything on the menu, it looks like it is on a "standing still mode", I can't see if I pick up the GDI or the NOD campaign on whatever difficulty I want to, so I don't want to imagine what would it be if I'd like to play a Skirmish map.
I've closed every program, except Mozilla Firefox and the ones necessary to run my computer, no influence on the game whatsoever.