I used to get around 1h of Internet time (modem) per week. I used this to download stuff that I could use for the rest of the week.
One time I started downloading a game, but a bit too late so I never got to finish the download before my time was up. Of course the game would not work as it was only partially downloaded (IIRC it was a zip file, but not 100% sure). There was some message from Windows telling me that there was something wrong with the exe. But I continued trying to open the game over and over again (maybe fiddled with the properties?) and one day it magically started, ran for a while and then crashed. It was possible to restart it, but it would crash at the same point every time.
It's still a mystery how it was possible, I guess it only had "content" left and the exe itself was fine, but that doesn't really explain why Windows initially refused to start it.