I'm trying to open one DDI file that has nothing to do with my system, it's just for the sake of my curiosity. I tried opening it in Notepad which, obviously, didn't work, so, I researched on the internet about DDI files. There was one site that offered a trial version of some program that, as they said, can open any file. I tried installing it and it froze and didn't work. My question is: Which program, that actually works, can open a DDI file?