Let me guess, you disabled aero/desktop composition?
All of the functions you describe result in a windows "save as" or "load" pop-up, similar to the dialog boxes you would get when saving/loading a file in notepad.
If you have disabled aero graphics, windows can't overlay that pop-up on top of the game interface.
Enable aero/desktop composition (either globally via the control panel, or just for the sim by right-clicking on launcher.exe and going to its properties) and try it again.
Let me know if it works out for you, cheers
