First thing to check is if the program's name is correct. I can tell the path is, or you would have got an error from the cd command, but I can't verify if the program itself is called megaglest as I still have 3.47 or something (TRYING to download now, but going very slow and download already stopped once...) where the program is called "glest_game". I recall it was renamed, but don't know what to, so use Windows Explorer to navigate to that folder ("C:\Programmi\MegaGlest") and see what the program's name is. It must be related to the program's name, as that's the only time you get that default windows error, otherwise, you'd at the very least, get a game error (or no error if Glest misbehaves).