Really, have you put it back where it came from and tried running the game? I once tried to get music off a different game by opening a file with Windows Media Player. It didn't work, but it didn't affect the file at all.
All you've done is tell your computer that if a user tries to open that file (and all .dat files), the computer should open it using notepad. I really doubt it will have changed the file in any way, unless you messed with it after opening it. Put your backup copy back where it came from and try and run the game.
|